DETAILED ACTION
This correspondence is in response to the communications received 10/16/2023. Claims 1-4 and 6-20 are pending.
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Information Disclosure Statement
The information disclosure statements (IDS) submitted on 01/10/2024 and 03/05/2024 have been considered by the examiner and made of record in the application file.
Drawings
The drawings are objected to because the text in Figs. 3A and 3B ead. Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. The figure or figure number of an amended drawing should not be labeled as “amended.” If a drawing figure is to be canceled, the appropriate figure must be removed from the replacement sheet, and where necessary, the remaining figures must be renumbered and appropriate changes made to the brief description of the several views of the drawings for consistency. Additional replacement sheets may be necessary to show the renumbering of the remaining figures. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
Claim Objections
The numbering of claims is not in accordance with 37 CFR 1.126 which requires the original numbering of the claims to be preserved throughout the prosecution. When claims are canceled, the remaining claims must not be renumbered. When new claims are presented, they must be numbered consecutively beginning with the number next following the highest numbered claims previously presented (whether entered or not).
Claim 5 was omitted from the original claim numbering. Appropriate correction is required.
Claim 16 is objected to because of the following informalities: Claim 16 contains two instances of the word "and" where the first instance appears to be erroneous. Appropriate correction is required.
Claim Interpretation
Claim 7 requires the limitation “heating the substrate to a temperature between about room temperature and about 500ºC”. For the purposes of examination, room temperature is defined as 15° - 25°C per the Merriam-Webster Dictionary.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 7 and 8 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
The term “about” in claims 7 and 8 is a relative term which renders the claims indefinite. The term “about” is not defined by the claims, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. The term "about" .
Applicant’s Claim to Figure Comparison
It is noted that this comparison is merely for the benefit of reviewers of this office action during prosecution, to allow for an understanding of the examiner’s interpretation of the Applicant’s independent claims as compared to disclosed embodiments in Applicant’s Figures. No response or comments are necessary from Applicant.
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Regarding claim 1, a method for fabricating a ferroelectric device, the method comprising:
providing a lower electrode layer (200) on a substrate (20);
forming a retention enhancement layer (220) by oxidizing a surface of the lower electrode layer (as seen in Fig. 2D) using a gas phase oxidation process (see [0013]); and
depositing a ferroelectric high-k metal oxide layer (240) over the retention enhancement layer (as seen in Fig. 2D) using a vapor deposition process (see [0020] and [0021]).
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1 and 9-15 are rejected under 35 U.S.C. 103 as being unpatentable over Lee et al. (US 6,987,308 B2, hereinafter “Lee”) in view of Jeon (US 9,754,960 B2, hereinafter “Jeon”) in view of Lee et al. (US 20220320123 A1, hereinafter ‘123).
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Regarding claim 1, Figs. 2, 4, and 5A-5D of Lee disclose a method for fabricating a ferroelectric device (see title, further “FIGS. 5A to 5D are sectional views showing a process of fabricating a semiconductor device having a stack type capacitor”, col 4, line 67 and col. 5, lines 1 and 2) the method comprising:
providing a lower electrode layer (“a lower electrode conductive film is formed on the interlayer insulating film 226 in which the contact plug 230 is formed, and may then be patterned by a photolithography process to form a stack type lower electrode 232”, col. 5, lines 39-43) on a substrate (“substrate 202”, as seen in Fig. 5D, 232 is on 202);
forming a retention enhancement layer (“metal oxide film 234”, Lee does not specify that 234 is a retention enhancement layer, but a secondary reference will be used to teach this below) by oxidizing a surface of the lower electrode layer using a gas phase oxidation process (“A specific process condition can be created to cause the surface of the lower electrode 232 to react with oxygen to form the metal oxide film 234. This oxidation reaction is influenced by the amount of oxygen, oxygen partial pressure, reaction temperature, pressure and surface properties of the lower electrode 232.”, col. 5, lines 62-67); and
depositing a ferroelectric high-k metal oxide layer over the retention enhancement layer (“ferroelectric film 240 is conformally formed on the lower electrode 232 on which the metal oxide film 234 is formed”, col. 6, lines 18-20, Lee does not specify that 240 is a high-k metal oxide, only that “The ferroelectric film may be formed from one or more materials selected from a group consisting of PZT, SBT, SBTN and BLT, and which can contain dopants such as Bi-SiOx, Ca, Mn and/or La”, col. 6, lines 21-24, thus 240 is a ferroelectric metal oxide, and a secondary reference will be used below to define 240 as a high-k material) using a vapor deposition process (“The ferroelectric film may be formed while supplying source gas, oxygen gas and/or other inert gas”, col. 6, lines 24-26).
Figs. 2, 4, and 5A-5D of Lee fail to specify “a retention enhancement layer; and
a ferroelectric high-k metal oxide layer”.
However, in a device that is reasonably pertinent to the particular problem with which the inventor was concerned, Jeon teaches a retention enhancement layer (“The charge storage film may include a nitride layer or a metal oxide film.”, col. 8, lines 5-6, therefore, the metal oxide film 234 formed by Lee can serve to storage charge, thus 234 of Lee enhances the charge retention capabilities of the ferroelectric device of Lee).
Therefore, it would have been obvious to one having ordinary skill in the art at the time the invention was effectively filed to implement “a retention enhancement layer” as taught by Jeon in the system of Lee for the purpose of improving the charge storage capability of a ferroelectric device thereby increasing its capacitance.
However, in a similar field of endeavor, Figs. 8-21 of ‘123 teach a ferroelectric high-k metal oxide layer (“In some embodiments, the ferroelectric switching layer 1402 may comprise hafnium oxide, hafnium zirconium oxide (HZO), lead zirconate titanate (PZT), or the like”, [0068], and as per [0030], these materials are high-k dielectrics, thus 240 of Lee which can be made of PZT, is a ferroelectric high-k metal oxide).
Therefore, it would have been obvious to one having ordinary skill in the art at the time the invention was effectively filed to implement “a ferroelectric high-k metal oxide layer” as taught by ‘123 in the system of Lee in combination with Jeon for the purpose of increasing the dielectric constant of the oxide layer enabling a reduction in device thickness while preventing dielectric breakdown thereby maintaining device functionality.
Regarding claim 9, Figs. 2, 4, and 5A-5D of Lee in combination with Jeon and Figs. 8-21 of ’123 disclose the method of claim 1, Figs. 2, 4, and 5A-5D of Lee further disclose wherein the ferroelectric high-k metal oxide layer is in direct physical contact with the retention enhancement layer (as seen in Fig. 5D, 240 is in direct physical contact with 234).
Regarding claim 10, Figs. 2, 4, and 5A-5D of Lee in combination with Jeon and Figs. 8-21 of ’123 disclose the method of claim 1, Figs. 2, 4, and 5A-5D of Lee further disclose further comprising depositing an upper electrode layer above the ferroelectric high-k metal oxide layer (“An upper electrode 242 is formed on the ferroelectric film 240”, col. 4, lines 60-61).
Regarding claim 11, Figs. 2, 4, and 5A-5D of Lee in combination with Jeon and Figs. 8-21 of ’123 disclose the method of claim 10, Figs. 2, 4, and 5A-5D of Lee further disclose wherein the upper electrode layer is in direct physical contact with the ferroelectric high-k metal oxide layer (as seen in Fig. 4, 242 is in direct physical contact with 240).
Regarding claim 12, Figs. 2, 4, and 5A-5D of Lee in combination with Jeon and Figs. 8-21 of ’123 disclose the method of claim 10, Figs. 8-21 of ’123 further disclose wherein the upper electrode layer includes a tungsten (W) metal layer (“a top electrode layer 1502 is formed over the ferroelectric switching layer 1402. The top electrode layer 1502 may comprise a metal, a metal nitride, or the like. In some embodiments, the top electrode layer 1502 may comprise tungsten, tantalum, tantalum nitride, titanium, titanium nitride, ruthenium, platinum, iridium, or the like. In some embodiments, the top electrode layer 1502 may be formed by a deposition process (e.g., a PVD process, a CVD process, a PE-CVD process, or the like)”, [0069], 1502 of ‘123 is equivalent to 242 of Lee).
Regarding claim 13, Figs. 2, 4, and 5A-5D of Lee in combination with Jeon and Figs. 8-21 of ’123 disclose the method of claim 1, Figs. 8-21 of ’123 further disclose wherein the lower electrode layer includes a titanium (Ti) metal layer, a tungsten (W) metal layer, or a laminate thereof (“a bottom electrode via layer 1004 is formed over the diffusion barrier layer 1002. ... In some embodiments, the bottom electrode via layer 1004 may comprise a metal, a metal nitride, or the like. For example, the bottom electrode via layer 1004 may comprise tungsten, tantalum nitride, titanium nitride, ruthenium, platinum, iridium, or the like. In some embodiments, the diffusion barrier layer 1002 and the bottom electrode via layer 1004 may be formed by deposition processes (e.g., a PVD process, a CVD process, a PE-CVD process, or the like)”, [0063], 1004 of ‘123 is equivalent to 232 of Lee).
Regarding claim 14, Figs. 2, 4, and 5A-5D of Lee in combination with Jeon and Figs. 8-21 of ’123 disclose the method of claim 1, Figs. 8-21 of ’123 further disclose wherein the ferroelectric high-k metal oxide layer includes hafnium oxide (HfOx), zirconium oxide (ZrOx), or hafnium zirconium oxide (HfZrOx) (As previously mentioned, 240 of Lee is formed of PZT, however, ‘123 teaches “the ferroelectric switching layer 1402 may comprise hafnium oxide, hafnium zirconium oxide (HZO), lead zirconate titanate (PZT), or the like”, [0068], thus it would be obvious to one having ordinary skill in the art to substitute the PZT of 240 of Lee for hafnium oxide or hafnium zirconium oxide as taught by ‘123).
Regarding claim 15, Figs. 2, 4, and 5A-5D of Lee in combination with Jeon and Figs. 8-21 of ’123 disclose the method of claim 1, Figs. 2, 4, and 5A-5D of Lee further disclose wherein depositing the ferroelectric high-k metal oxide layer includes exposing the substrate to a metal-containing precursor vapor (Lee does not specifically disclose a metal-containing precursor vapor, however Lee does state “The ferroelectric film may be formed while supplying source gas, oxygen gas and/or other inert gas”, col. 6, lines 24-26, as neither the oxygen gas nor the inert gas would contain Pb or Ti, source gas must necessarily be a metal-containing precursor vapor, and as 240 is on 202, 202 is exposed to the source gas), and exposing the substrate to an oxygen-containing gas (as mentioned above, 202 is exposed to an oxygen gas).
Claims 2-4, 7, 8, 16 and 17 are rejected under 35 U.S.C. 103 as being unpatentable over Lee et al. (US 6,987,308 B2, hereinafter “Lee”) in view of Jeon (US 9,754,960 B2, hereinafter “Jeon”) in view of Lee et al. (US 20220320123 A1, hereinafter ‘123) in view of Rhodes (US 6,646,298 B2, hereinafter “Rhodes”).
Regarding claim 2, Figs. 2, 4, and 5A-5D of Lee in combination with Jeon and Figs. 8-21 of ’123 disclose the method of claim 1.
Figs. 2, 4, and 5A-5D of Lee fail to disclose “wherein forming the retention enhancement layer includes exposing the lower electrode layer to ozone”.
However, in a similar field of endeavor, Fig. 4 of Rhodes teaches wherein forming the retention enhancement layer includes exposing the lower electrode layer to ozone (“Surface 24 of the oxygen-doped metal electrode 22 is then oxidized. The oxidation is preferably a gas plasma treatment under oxidizing conditions and is preferably carried out at a temperature of between about 250 to about 500 °C., and preferably about 400 °C. using a gas containing either O2 or O3. For example, gas plasma may be formed using microwave power on oxygen or ozone gas sufficient to dissociate the oxygen molecules into individual activated atoms. With this step, the surface of metal electrode 22 is oxidized.”, col. 3, lines 43-51, where 22 of Rhodes is equivalent to 232 of Lee).
Therefore, it would have been obvious to one having ordinary skill in the art at the time the invention was effectively filed to implement “wherein forming the retention enhancement layer includes exposing the lower electrode layer to ozone” as taught by Rhodes in the system of Park in combination with Jeon and ‘123 for the purpose of providing “at least the surface, and preferably an upper portion of the electrode, with enough oxygen so that electrode 22 will be stable with the high dielectric constant oxide dielectric layer 26” (col 3, lines 52-55).
Regarding claim 3, Figs. 2, 4, and 5A-5D of Lee in combination with Jeon and Figs. 8-21 of ’123 disclose the method of claim 1.
Figs. 2, 4, and 5A-5D of Lee fail to disclose “wherein forming the retention enhancement layer includes exposing the lower electrode layer to plasma-excited O2 gas”.
However, in a similar field of endeavor, Fig. 4 of Rhodes teaches wherein forming the retention enhancement layer includes exposing the lower electrode layer to plasma-excited O2 gas (“Surface 24 of the oxygen-doped metal electrode 22 is then oxidized. The oxidation is preferably a gas plasma treatment under oxidizing conditions and is preferably carried out at a temperature of between about 250 to about 500 °C., and preferably about 400 °C. using a gas containing either O2 or O3. For example, gas plasma may be formed using microwave power on oxygen or ozone gas sufficient to dissociate the oxygen molecules into individual activated atoms. With this step, the surface of metal electrode 22 is oxidized.”, col. 3, lines 43-51, where 22 of Rhodes is equivalent to 232 of Lee).
Therefore, it would have been obvious to one having ordinary skill in the art at the time the invention was effectively filed to implement “wherein forming the retention enhancement layer includes exposing the lower electrode layer to plasma-excited O2 gas” as taught by Rhodes in the system of Park in combination with Jeon and ‘123 for the purpose of providing “at least the surface, and preferably an upper portion of the electrode, with enough oxygen so that electrode 22 will be stable with the high dielectric constant oxide dielectric layer 26” (col 3, lines 52-55).
Regarding claim 4, Figs. 2, 4, and 5A-5D of Lee in combination with Jeon and Figs. 8-21 of ’123 disclose the method of claim 1.
Figs. 2, 4, and 5A-5D of Lee fail to disclose “wherein forming the retention enhancement layer includes using a microwave excitation source to excite O2 gas, and exposing the lower electrode layer to the plasma-excited O2 gas”.
However, in a similar field of endeavor, Fig. 4 of Rhodes teaches wherein forming the retention enhancement layer includes using a microwave excitation source to excite O2 gas, and exposing the lower electrode layer to the plasma-excited O2 gas (“Surface 24 of the oxygen-doped metal electrode 22 is then oxidized. The oxidation is preferably a gas plasma treatment under oxidizing conditions and is preferably carried out at a temperature of between about 250 to about 500 °C., and preferably about 400 °C. using a gas containing either O2 or O3. For example, gas plasma may be formed using microwave power on oxygen or ozone gas sufficient to dissociate the oxygen molecules into individual activated atoms. With this step, the surface of metal electrode 22 is oxidized.”, col. 3, lines 43-51, where 22 of Rhodes is equivalent to 232 of Lee).
Therefore, it would have been obvious to one having ordinary skill in the art at the time the invention was effectively filed to implement “wherein forming the retention enhancement layer includes using a microwave excitation source to excite O2 gas, and exposing the lower electrode layer to the plasma-excited O2 gas” as taught by Rhodes in the system of Park in combination with Jeon and ‘123 for the purpose of providing “at least the surface, and preferably an upper portion of the electrode, with enough oxygen so that electrode 22 will be stable with the high dielectric constant oxide dielectric layer 26” (col 3, lines 52-55).
Regarding claim 7, Figs. 2, 4, and 5A-5D of Lee in combination with Jeon and Figs. 8-21 of ’123 disclose the method of claim 1.
Figs. 2, 4, and 5A-5D of Lee fail to disclose “wherein forming the retention enhancement layer further includes heating the substrate to a temperature between about room temperature and about 500ºC”.
However, in a similar field of endeavor, Fig. 4 of Rhodes teaches wherein forming the retention enhancement layer further includes heating the substrate to a temperature between about room temperature and about 500ºC (“Surface 24 of the oxygen-doped metal electrode 22 is then oxidized. The oxidation is preferably a gas plasma treatment under oxidizing conditions and is preferably carried out at a temperature of between about 250 to about 500 °C., and preferably about 400 °C. using a gas containing either O2 or O3. For example, gas plasma may be formed using microwave power on oxygen or ozone gas sufficient to dissociate the oxygen molecules into individual activated atoms. With this step, the surface of metal electrode 22 is oxidized.”, col. 3, lines 43-51, where 22 of Rhodes is equivalent to 232 of Lee).
Therefore, it would have been obvious to one having ordinary skill in the art at the time the invention was effectively filed to implement “wherein forming the retention enhancement layer further includes heating the substrate to a temperature between about room temperature and about 500ºC” as taught by Rhodes in the system of Park in combination with Jeon and ‘123 for the purpose of providing “at least the surface, and preferably an upper portion of the electrode, with enough oxygen so that electrode 22 will be stable with the high dielectric constant oxide dielectric layer 26” (col 3, lines 52-55).
Regarding claim 8, Figs. 2, 4, and 5A-5D of Lee in combination with Jeon and Figs. 8-21 of ’123 disclose the method of claim 1.
Figs. 2, 4, and 5A-5D of Lee fail to disclose “wherein forming the retention enhancement layer further includes heating the substrate to a temperature between about 250ºC and about 300ºC”.
However, in a similar field of endeavor, Fig. 4 of Rhodes teaches wherein forming the retention enhancement layer further includes heating the substrate to a temperature between about 250ºC and about 300ºC (“Surface 24 of the oxygen-doped metal electrode 22 is then oxidized. The oxidation is preferably a gas plasma treatment under oxidizing conditions and is preferably carried out at a temperature of between about 250 to about 500 °C., and preferably about 400 °C. using a gas containing either O2 or O3. For example, gas plasma may be formed using microwave power on oxygen or ozone gas sufficient to dissociate the oxygen molecules into individual activated atoms. With this step, the surface of metal electrode 22 is oxidized.”, col. 3, lines 43-51, where 22 of Rhodes is equivalent to 232 of Lee. Rhodes does not directly disclose heating the substrate to a temperature between about 250ºC and about 300ºC, however, Rhodes does teach heating the substrate to a temperature between about 250 and 500 °C. MPEP 2144.05 I states “In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art a prima facie case of obviousness exists.”).
Therefore, it would have been obvious to one having ordinary skill in the art at the time the invention was effectively filed to implement “wherein forming the retention enhancement layer further includes heating the substrate to a temperature between about 250ºC and about 300ºC” as taught by Rhodes in the system of Park in combination with Jeon and ‘123 for the purpose of providing “at least the surface, and preferably an upper portion of the electrode, with enough oxygen so that electrode 22 will be stable with the high dielectric constant oxide dielectric layer 26” (col 3, lines 52-55).
Regarding claim 16, Figs. 2, 4, and 5A-5D of Lee disclose a method for fabricating a ferroelectric device (see title, further “FIGS. 5A to 5D are sectional views showing a process of fabricating a semiconductor device having a stack type capacitor”, col 4, line 67 and col. 5, lines 1 and 2), the method comprising:
providing a lower electrode layer (“a lower electrode conductive film is formed on the interlayer insulating film 226 in which the contact plug 230 is formed, and may then be patterned by a photolithography process to form a stack type lower electrode 232”, col. 5, lines 39-43) on a substrate (“substrate 202”, as seen in Fig. 5D, 232 is on 202);
forming a retention enhancement layer (“metal oxide film 234”, Lee does not specify that 234 is a retention enhancement layer, but a secondary reference will be used to teach this below) by oxidizing a surface of the lower electrode layer using ozone (“A specific process condition can be created to cause the surface of the lower electrode 232 to react with oxygen to form the metal oxide film 234. This oxidation reaction is influenced by the amount of oxygen, oxygen partial pressure, reaction temperature, pressure and surface properties of the lower electrode 232.”, col. 5, lines 62-67, Lee does not disclose using ozone, however, a secondary reference will be used to teach this below); and
depositing a ferroelectric hafnium zirconium oxide (HfZrOx) layer (“ferroelectric film 240 is conformally formed on the lower electrode 232 on which the metal oxide film 234 is formed”, col. 6, lines 18-20, Lee does not specify that 240 is HfZrOx, only that “The ferroelectric film may be formed from one or more materials selected from a group consisting of PZT, SBT, SBTN and BLT, and which can contain dopants such as Bi-SiOx, Ca, Mn and/or La”, col. 6, lines 21-24”, thus a secondary reference will be used to substitute in HfZrOx below) in direct physical contact with the retention enhancement (as seen in Fig. 5D, 240 is in direct contact with 234) layer using a vapor deposition process (“The ferroelectric film may be formed while supplying source gas, oxygen gas and/or other inert gas”, col. 6, lines 24-26); and
depositing an upper electrode layer above the ferroelectric hafnium zirconium oxide layer (“An upper electrode 242 is formed on the ferroelectric film 240”, col. 4, lines 60-61).
Figs. 2, 4, and 5A-5D of Lee fail to specify “forming a retention enhancement layer by oxidizing a surface of the lower electrode layer using ozone; and
depositing a ferroelectric hafnium zirconium oxide (HfZrOx) layer”.
However, in a device that is reasonably pertinent to the particular problem with which the inventor was concerned, Jeon teaches a retention enhancement layer (“The charge storage film may include a nitride layer or a metal oxide film.”, col. 8, lines 5-6, therefore, the metal oxide film 234 formed by Lee can serve to storage charge, thus 234 of Lee enhances the charge retention capabilities of the ferroelectric device of Lee).
Therefore, it would have been obvious to one having ordinary skill in the art at the time the invention was effectively filed to implement “a retention enhancement layer” as taught by Jeon in the system of Lee for the purpose of improving the charge storage capability of a ferroelectric device thereby increasing its capacitance.
However, in a similar field of endeavor, Fig. 4 of Rhodes teaches forming a retention enhancement layer by oxidizing a surface of the lower electrode layer using ozone (“Surface 24 of the oxygen-doped metal electrode 22 is then oxidized. The oxidation is preferably a gas plasma treatment under oxidizing conditions and is preferably carried out at a temperature of between about 250 to about 500 °C., and preferably about 400 °C. using a gas containing either O2 or O3. For example, gas plasma may be formed using microwave power on oxygen or ozone gas sufficient to dissociate the oxygen molecules into individual activated atoms. With this step, the surface of metal electrode 22 is oxidized.”, col. 3, lines 43-51, where 22 of Rhodes is equivalent to 232 of Lee).
Therefore, it would have been obvious to one having ordinary skill in the art at the time the invention was effectively filed to implement “forming a retention enhancement layer by oxidizing a surface of the lower electrode layer using ozone” as taught by Rhodes in the system of Park in combination with Jeon for the purpose of providing “at least the surface, and preferably an upper portion of the electrode, with enough oxygen so that electrode 22 will be stable with the high dielectric constant oxide dielectric layer 26” (col 3, lines 52-55).
However, in a similar field of endeavor, Figs. 8-21 of ‘123 teach depositing a ferroelectric hafnium zirconium oxide (HfZrOx) layer (“In some embodiments, the ferroelectric switching layer 1402 may comprise hafnium oxide, hafnium zirconium oxide (HZO), lead zirconate titanate (PZT), or the like”, [0068], thus it would be obvious to one having ordinary skill in the art to substitute the PZT of 240 of Lee for hafnium zirconium oxide as taught by ‘123).
Therefore, it would have been obvious to one having ordinary skill in the art at the time the invention was effectively filed to implement “depositing a ferroelectric hafnium zirconium oxide (HfZrOx) layer” as taught by ‘123 in the system of Lee in combination with Jeon and Rhodes for the purpose of eliminating the use of lead in the manufacturing process without sacrificing device functionality.
Regarding claim 17, Figs. 2, 4, and 5A-5D of Lee in combination with Jeon, Fig. 4 of Rhodes, and Figs. 8-21 of ’123 disclose the method of claim 16, Figs. 8-21 of ’123 further disclose wherein the lower electrode layer includes a titanium (Ti) metal layer, a tungsten (W) metal layer, or a laminate thereof (“a bottom electrode via layer 1004 is formed over the diffusion barrier layer 1002. ... In some embodiments, the bottom electrode via layer 1004 may comprise a metal, a metal nitride, or the like. For example, the bottom electrode via layer 1004 may comprise tungsten, tantalum nitride, titanium nitride, ruthenium, platinum, iridium, or the like. In some embodiments, the diffusion barrier layer 1002 and the bottom electrode via layer 1004 may be formed by deposition processes (e.g., a PVD process, a CVD process, a PE-CVD process, or the like)”, [0063], 1004 of ‘123 is equivalent to 232 of Lee), and the upper electrode layer includes a tungsten (W) metal layer (“a top electrode layer 1502 is formed over the ferroelectric switching layer 1402. The top electrode layer 1502 may comprise a metal, a metal nitride, or the like. In some embodiments, the top electrode layer 1502 may comprise tungsten, tantalum, tantalum nitride, titanium, titanium nitride, ruthenium, platinum, iridium, or the like. In some embodiments, the top electrode layer 1502 may be formed by a deposition process (e.g., a PVD process, a CVD process, a PE-CVD process, or the like)”, [0069], 1502 of ‘123 is equivalent to 242 of Lee).
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Lee et al. (US 6,987,308 B2, hereinafter “Lee”) in view of Jeon (US 9,754,960 B2, hereinafter “Jeon”) in view of Lee et al. (US 20220320123 A1, hereinafter ‘123) in view of Rhodes (US 6,646,298 B2, hereinafter “Rhodes”) in view of Li et al. (US 20190382886 A1, hereinafter “Li”).
Regarding claim 6, Figs. 2, 4, and 5A-5D of Lee in combination with Jeon, Figs. 8-21 of ’123, and Fig. 4 of Rhodes disclose the method of claim 4.
Fig. 4 of Rhodes fails to disclose “wherein forming the retention enhancement layer using a remote plasma excitation source to excite O2 gas, and exposing the lower electrode layer to the plasma-excited O2 gas”.
However, in a device that is reasonably pertinent to the particular problem with which the inventor was concerned, Li teaches wherein forming the retention enhancement layer using a remote plasma excitation source to excite O2 gas, and exposing the lower electrode layer to the plasma-excited O2 gas (“at least one activated species is an oxidant generated by action of a plasma source or a remote microwave source upon a species selected from the group consisting of water vapor, ozone, oxygen, oxygen/helium, oxygen/argon, nitrogen oxides, carbon dioxide, hydrogen peroxide, organic peroxides, and mixtures thereof”, [0012], therefore, the plasma source of Rhodes can be a remote microwave source)
Therefore, it would have been obvious to one having ordinary skill in the art at the time the invention was effectively filed to implement “wherein forming the retention enhancement layer using a remote plasma excitation source to excite O2 gas, and exposing the lower electrode layer to the plasma-excited O2 gas” as taught by Li in the system of Lee in combination with Jeon, ‘123, and Rhodes for the purpose of mitigating plasma induced damage to the ferroelectric device by using a plasma source that does not directly interact with the device.
Claims 18-20 are rejected under 35 U.S.C. 103 as being unpatentable over Lee et al. (US 6,987,308 B2, hereinafter “Lee”) in view of Lång et al. (US 20220310875 A1, hereinafter “Lång”) in view of Jeon (US 9,754,960 B2, hereinafter “Jeon”) in view of Lee et al. (US 20220320123 A1, hereinafter ‘123).
Regarding claim 18, Figs. 2, 4, and 5A-5D of Lee disclose a method for fabricating a ferroelectric device (see title, further “FIGS. 5A to 5D are sectional views showing a process of fabricating a semiconductor device having a stack type capacitor”, col 4, line 67 and col. 5, lines 1 and 2) the method comprising:
providing, in a first process chamber (it would be obvious to one having ordinary skill in the art that the method disclosed by Lee is performed in a process chamber, hereinafter the “FPC”), a lower electrode layer (“a lower electrode conductive film is formed on the interlayer insulating film 226 in which the contact plug 230 is formed, and may then be patterned by a photolithography process to form a stack type lower electrode 232”, col. 5, lines 39-43) on a substrate (“substrate 202”, as seen in Fig. 5D, 232 is on 202);
forming a retention enhancement layer (“metal oxide film 234”, Lee does not specify that 234 is a retention enhancement layer, but a secondary reference will be used to teach this below) by oxidizing a surface of the lower electrode layer using a gas phase oxidation process (“A specific process condition can be created to cause the surface of the lower electrode 232 to react with oxygen to form the metal oxide film 234. This oxidation reaction is influenced by the amount of oxygen, oxygen partial pressure, reaction temperature, pressure and surface properties of the lower electrode 232.”, col. 5, lines 62-67) in the first process chamber (as forming 234 is the first step after providing 232 on 202, the oxidation of 232 would occur in the chamber where 232 is provided on 202, that is, in the FPC);
depositing a ferroelectric high-k metal oxide layer over the retention enhancement layer (“ferroelectric film 240 is conformally formed on the lower electrode 232 on which the metal oxide film 234 is formed”, col. 6, lines 18-20, Lee does not specify that 240 is a high-k metal oxide, only that “The ferroelectric film may be formed from one or more materials selected from a group consisting of PZT, SBT, SBTN and BLT, and which can contain dopants such as Bi-SiOx, Ca, Mn and/or La”, col. 6, lines 21-24, thus 240 is a ferroelectric metal oxide, and a secondary reference will be used below to define 240 as a high-k material) using a vapor deposition process (“The ferroelectric film may be formed while supplying source gas, oxygen gas and/or other inert gas”, col. 6, lines 24-26) in a second process chamber (Lee does not specify utilizing a second process chamber, therefore a secondary reference will be used to teach this below).
Figs. 2, 4, and 5A-5D of Lee fail to specify “forming a retention enhancement layer by oxidizing a surface of the lower electrode layer using a gas phase oxidation process in the first process chamber;
transferring the substrate into a second process chamber; and
depositing a ferroelectric high-k metal oxide layer over the retention enhancement layer using a vapor deposition process in a second process chamber”.
However, in a device that is reasonably pertinent to the particular problem with which the inventor was concerned, Jeon teaches a retention enhancement layer (“The charge storage film may include a nitride layer or a metal oxide film.”, col. 8, lines 5-6, therefore, the metal oxide film 234 formed by Lee can serve to storage charge, thus 234 of Lee enhances the charge retention capabilities of the ferroelectric device of Lee).
Therefore, it would have been obvious to one having ordinary skill in the art at the time the invention was effectively filed to implement “a retention enhancement layer” as taught by Jeon in the system of Lee for the purpose of improving the charge storage capability of a ferroelectric device thereby increasing its capacitance.
However, in a device that is reasonably pertinent to the particular problem with which the inventor was concerned, Fig. 4 of Lång teaches forming a retention enhancement layer by oxidizing a surface of the lower electrode layer using a gas phase oxidation process in the first process chamber (“Step S2… the mesa is processed to form the first terminating oxide layer. The mesa is controllably oxidized to form one or more terminating oxide layers on the surface of the mesa structure”, [0090-0092], where the mesa structure of Lång is equivalent to 232 of Lee, the first terminating oxide layer of Lång is equivalent to 234 of Less, and step S2 of Lång occurs in a chamber equivalent to FPC of Lee);
transferring the substrate into a second process chamber (“after the creation of the terminating oxide layer(s), the optoelectronic device can be transferred for the deposition of an overcoating”, [0104]); and
depositing a ferroelectric high-k metal oxide layer over the retention enhancement layer using a vapor deposition process (“Step S3 … the optoelectronic device can be transferred for the deposition of an overcoating. The overcoating deposition can be conducted for instance by using Chemical Vapour Deposition (CVD), ALD or PECVD or by sputtering deposition”, [0103-0104]) in a second process chamber (“In the manufacturing process the steps S1, S2 and S3 are typically done in separate chambers”, [0111], thus the deposition of 240 of Lee can be done in a second process chamber, separate from the FPC)
Therefore, it would have been obvious to one having ordinary skill in the art at the time the invention was effectively filed to implement “forming a retention enhancement layer by oxidizing a surface of the lower electrode layer using a gas phase oxidation process in the first process chamber;
transferring the substrate into a second process chamber; and
depositing a ferroelectric high-k metal oxide layer over the retention enhancement layer using a vapor deposition process in a second process chamber” as taught by Lång in the system of Lee in combination with Jeon for the purpose of using specialized processing tools designed for each manufacturing step (“the equipment will have different components to monitor and to produce different steps of the process S1, S2 and S3, such as pressure and temperature gages, heaters, vacuum pumps, plasma sources, plasma guns, sputtering heads, gas lines, leak valves etc”, [0111])
However, in a similar field of endeavor, Figs. 8-21 of ‘123 teach a ferroelectric high-k metal oxide layer (“In some embodiments, the ferroelectric switching layer 1402 may comprise hafnium oxide, hafnium zirconium oxide (HZO), lead zirconate titanate (PZT), or the like”, [0068], and as per [0030], these materials are high-k dielectrics, thus 240 of Lee which can be made of PZT, is a ferroelectric high-k metal oxide).
Therefore, it would have been obvious to one having ordinary skill in the art at the time the invention was effectively filed to implement “a ferroelectric high-k metal oxide layer” as taught by ‘123 in the system of Lee in combination with Jeon and Lång for the purpose of increasing the dielectric constant of the oxide layer enabling a reduction in device thickness while preventing dielectric breakdown thereby maintaining device functionality.
wherein the ferroelectric high-k metal oxide layer is in direct physical contact with the retention enhancement layer (as seen in Fig. 5D, 240 is in physical contact with 234).
Regarding claim 19, Figs. 2, 4, and 5A-5D of Lee in combination with Jeon, Fig. 4 of Lång, and Figs. 8-21 of ’123 disclose the method of claim 18, Figs. 2, 4, and 5A-5D of Lee further disclose wherein the first process chamber is configured for performing surface oxidation of the lower electrode layer to form the retention enhancement layer (as discussed previously FPC is configured for performing surface oxidation of 232 to form 234).
Fig. 4 of Lång fails to disclose “wherein the second process chamber is configured to perform atomic layer deposition (ALD) of the ferroelectric high-k oxide layer”.
However, in a similar field of endeavor, Figs. 23-30 of ‘123 teach wherein the second process chamber is configured to perform atomic layer deposition (ALD) of the ferroelectric high-k oxide layer (“a first ferroelectric switching layer 3402 is formed onto the bottom electrode layer 1202. In some embodiments, the first ferroelectric switching layer 3402 may be formed by way of a deposition process (e.g., PVD, CVD, PE-CVD, ALD, sputtering, etc.)”, [0119], where 3402 of ‘123 is equivalent to 240 of Lee and the deposition of 3402 occurs in the second process chamber taught by Lång, which as previously discussed, can be configured for ALD processing).
Therefore, it would have been obvious to one having ordinary skill in the art at the time the invention was effectively filed to implement “wherein the second process chamber is configured to perform atomic layer deposition (ALD) of the ferroelectric high-k oxide layer” as taught by ‘123 in the system of Lee in combination with Jeon, Lång, and ‘123 for the purpose of depositing the ferroelectric high-k oxide layer with high conformality and precise thickness control.
Regarding claim 20, Figs. 2, 4, and 5A-5D of Lee in combination with Jeon, Fig. 4 of Lång, and Figs. 8-21 of ’123 disclose the method of claim 18, Figs. 8-21 of ’123 further disclose wherein the ferroelectric high-k metal oxide layer includes hafnium oxide (HfOx), zirconium oxide (ZrOx), or hafnium zirconium oxide (HfZrOx) (As previously mentioned, 240 of Lee is formed of PZT, however, ‘123 teaches “the ferroelectric switching layer 1402 may comprise hafnium oxide, hafnium zirconium oxide (HZO), lead zirconate titanate (PZT), or the like”, [0068], thus it would be obvious to one having ordinary skill in the art to substitute the PZT of 240 of Lee for hafnium oxide or hafnium zirconium oxide as taught by ‘123).
Conclusion
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/BENJAMIN MICHAEL KUPP/Examiner, Art Unit 2893
/YARA B GREEN/Supervisor Patent Examiner, Art Unit 2893