The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
DETAILED ACTION
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claims 1 – 3, 5, 14, 15, and 18 are rejected under 35 U.S.C. 102(a)(2) as being anticipated by Zhou et al (US 2021/0373363 A1).
Regarding claim 1, Zhou discloses (Fig. 4D; Abstract; para. 0062 – 0073) a semiconductor device (a phase shifter/modulator in semiconductor material; Abstract), comprising:
a dielectric/insulator layer 420,460 (e.g., silicon dioxide; para. 0062, 0063, and 0065); and
an optical (phase) modulator structure, in the dielectric layer 420,460 (as seen in Fig. 4B), comprising:
a first region 446 including a first dopant type (e.g., n-type; para. 0072);
a second region 436, on a bottom surface of the first region 446 (as seen in Fig. 4D), including a second dopant type (p-type; “the second n-doped layer 446 on the second p-doped layer 436” at para. 0072); and
a third region 444, on a bottom surface of the second region 436 (as seen in Fig. 4D), including the first dopant type (n-type; “the second p-doped layer 436 on the first n-doped layer 444” at para. 0072),
wherein the first region 446, the second region 436, and the third region 444 correspond to a (U-shaped) P-N junction diode (as shown in Fig. 14) of the optical modulator structure (Abstract; para. 0054 and 0102 – 0107).
Regarding claim 2, Zhou teaches (Fig. 4D; para. 0072) that the device/modulator further comprises: a first supporting region 442, including the first (n-type) dopant type (para. 0072), connecting the first region 446 and the third region 444 to a first contact 440 (to which voltage V+ is applied via a metal electrode; para. 0060, 0065, and 0072).
Regarding claim 3, Zhou teaches (Fig. 4D; para. 0072) that the device/modulator further comprises: a second supporting region 432, including the second (p-type) dopant type (para. 0072), connecting the second region 432 to a second contact 430 (to which voltage V- is applied via a metal electrode; para. 0060, 0062, 0064, and 0072).
Regarding claim 5, Zhou teaches (Fig. 4D; para. 0072) that the first dopant type comprises at least one n-type dopant (e.g., “phosphorus or arsenic” at para. 0080), and the second dopant type comprises at least one p-type dopant (e.g., “boron or gallium” at para. 0080).
Regarding claim 14, Zhou discloses (Fig. 4D; Abstract; para. 0062 – 0073) a semiconductor structure (a phase shifter/modulator in semiconductor material; Abstract), comprising:
a dielectric/insulator layer 420,460 (e.g., silicon dioxide; para. 0062, 0063, and 0065); and
an optical (phase) modulator structure, in the dielectric layer 420,460 (as seen in Fig. 4B), comprising:
a first portion 436 of a P-N junction diode (defined by interfaces of portion doped with opposite polarities) of the optical modulator structure, wherein the first portion 436 includes a first dopant type (e.g., p-type; para. 0072); and
a second portion 446,442,444 of the P-N junction diode, wherein the second portion 446,442,444 includes a second dopant type (n-type; para. 0072), and wherein the second portion comprises:
a first segment 444 in contact with a bottom surface of the first portion 436 (“the second p-doped layer 436 on the first n-doped layer 444” at para. 0072);
a second segment 442 in contact with a side surface of the first portion 436 (Fig. 4D); and
a third segment 446 in contact with a top surface of the first portion 436 (“the second n-doped layer 446 on the second p-doped layer 436” at para. 0072).
Regarding claim 15, Zhou teaches (Fig. 4D) that the first and second portions define a U-shaped interface between them.
Regarding claim 18, Zhou teaches (Fig. 4D; para. 0072) that the disclosed modulator structure further comprises: a contact region 430 (to which voltage V- is applied via a metal electrode; para. 0060, 0062, 0064, and 0072) electrically connected to the first portion 436 of the P-N junction diode.
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 of this title, 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.
The factual inquiries set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 4, 7, 16, and 17 are rejected under 35 U.S.C. 103 as being unpatentable over Zhou.
Regarding claim 4, while Zhou teaches (para. 0072), by way of example but not limitation, that the first dopant type is the n-type and the second dopant type is the p-type, it would be obvious to a person of ordinary skill in the art that the doping polarities can be reversed, as the alternative design choice in which case the first dopant type comprises at least one p-type dopant, and the second dopant type comprises at least one n-type dopant.
Regarding claim 7, while Zhou states (para. 0006) a well-known fact that a phase modulator can be comprised in a Mach-Zehnder modulator (MZM) structure. Hence, Zhou renders obvious that the disclosed phase modulator (in Fig, 4B) can be comprised in an MZM structure in order to convert phase modulation into amplitude modulation (para. 0006).
Regarding claim 16 and 17, Zhou states that “Each of the p-doped layers 434 and 436 and the n-doped layers 444 and 446 may have a thickness of from 0.1 to 1 μm (e.g., 0.3-0.8 μm, or any thickness or range of thicknesses between 0.1 and 2 μm)” (para. 0073). Hence, Zhou does not limit a difference(s) between the thicknesses of any two layers to any particular value and/or relationship and renders obvious, as a matter of suitable/workable embodiments, that a thickness of the first portion can be greater relative to a thickness of the first segment and the third segment, and that a thickness of the first segment can be greater relative to a thickness of the third segment. It is also noted that it has been held that discovering the optimum or workable ranges of prior art involves only routine skill in the art. In re Aller, 105 USPQ 233.
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Zhou in view of Liu et al (US 2014/0341497 A1).
Regarding claim 6, Zhou renders obvious the use of the disclosed phase modulator in an MZM structure (as detailed above for claim 7), but does not cite a micro-ring (MRM) structure as another well-known intensity modulator type. However, Liu discloses (Fig. 1A; para. 0049 – 0056) a phase modulator with a bent/folded P-N junction (a shape similar to that in Figs. 4B and 4D of Zhou) and expressly teaches the application of the disclosed phase modulator in an MZM structure (Fig. 5A; para. 0080) and in an MRM structure (Fig. 6; para. 0004 and 0084).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention that the phase modulator of Zhou can be used, as a drop-in component, in an MRM structure, as a suitable application that is explicitly illustrated by Liu and enables an efficient intensity modulator.
Claims 8 – 13 are rejected under 35 U.S.C. 103 as being unpatentable over Gardes et al (US 2013/0188902 A1) in view of Poon et al (US 2017/0254955 A1).
Regarding claim 8, Gardes discloses (Figs. 2d and 2e; para. 0041 – 0046) a method, comprising:
forming (Fig. 2d), using a first (resist) mask 130, a first supporting region (thinner slab portion of 118) using a first dopant type 144 (e.g., p-type; para. 0041);
forming (Fig. 2e), using a second (resist) mask 132, a second supporting region (thinner slab portion of 120) using a second dopant type 146 (n-type; para. 0041).
Gardes considers only embodiments wherein a bent/folded P-N junction is formed by a stack of layers 118,120 that are deposited with opposite polarities (Fig. 2a) and subsequently processed by steps of etching and implantation at different angles. Gardes does not teach that a bent/folded P-N junction can be formed by multiple implantation steps with different energies. However, Poon discloses (Figs. 5A – 5F; para. 0065 – 0074) a method of forming a bent/folded/U-shaped P-N junction 124 (para. 0071) that comprises a step of doping (implantation), using a mask 162 and implantations at different energies:
a first region 142 with the first dopant type,
a second region 132 with the second dopant type, wherein the second region 142 is under the first region 142 (as seen in Fig. 5F); and
a third region 143 with the first dopant type, wherein the third region 143 is under the second region 132 (as seen in Fig. 5F), wherein the first region 142, the second region 132, and the third region 143 correspond to a P-N junction diode, and wherein the first region 142, the second region 132, and the third region 143 form a U-shaped interface 124 of the P-N junction diode (para. 0071).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention that the method of Gardes with implantation at different angles can be modified, in accordance with the teachings of Poon, to include implantations at different energies. The motivation is that a bent/folded/U-shaped P-N junction can be formed without requiring impanation at different angles which are more involved (“As compared with prior art manufacturing techniques, the above process eliminates the need for changing the implantation angle and builds the junction in 3 steps (1 step with the first dopant species, and 2 steps with the second dopant species. By comparison, the prior art methods require at least 4 implantation steps along with a varied implantation angle” at para. 0075 of Poon).
Regarding claim 9, the Gardes – Poon combination considers that the doping of the third (bottommost) region 143 using a greater implantation energy E2 (as identified in Fig. 5C) than that (E3 in Fig. 5E) used in doping the second (intermediate) region 132 or doping the first (uppermost) region 142.
Regarding claims 10 and 11, the Gardes – Poon combination renders obvious (Figs. 5C – 5E of Poon) that the doping of a first portion of the second region uses a first implantation energy; and that the doping of a second portion of the second region uses a second implantation energy.
Regarding claim 12, the Gardes – Poon combination considers that forming the first supporting region comprises (Fig. 2d of Gardes; para. 0041): doping the first supporting region using a first dopant material 144; and doping the first supporting region using a second dopant material 146.
Regarding claim 13, the Gardes – Poon combination considers (Fig. 2e of Gardes) that forming the second supporting region comprises: doping the second supporting region in a first implantation operation (with 148); and increasing a carrier concentration in the second supporting region using a second implantation operation (with 150) after the first implantation operation.
Claims 19 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Zhou in view of Gardes.
Regarding claim 19, Zhou states that the doped contact regions 430 and 440 are heavily doped and connected to metal electrodes which are not known in the drawings (para. 0065 and 0066). While Zhou does not further detail such structure, Gardes discloses (Fig. 1; para. 0029 – 0034) a semiconductor phase modulator (the same general type as that in Zhou) that comprises heavily doped regions 118a,120a (para. 0031) that are connected metal electrodes 124,126 (para. 0033). Gardes details that the disclosed modulator is manufactured by a processing sequence (Figs. 2a – 2f) involving multiple implantation steps and masks. Gardes details that the heavily doped regions 118a,120a are produced by an implantation step in Fig. 2f (para. 0047) through a photoresist mask 134 that creates a shadow effect in the corner regions, the shadow effect resulting in lightly doped regions 118b,120b in the layer 118 (compared Figs. 2f and 2g; “a second part 118b of relatively sparsely doped material (as commonly denoted p in the literature), that is, sparsely doped relative to the highly doped region 118a. Similarly, the n-type region 120 comprises a first part 120a of highly doped material (as commonly denoted n+ in the literature), and a second part 120b of relatively sparsely doped material (as commonly denoted n in the literature), that is, sparsely doped relative to the highly doped region 120a” at para. 0031).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention that the heavily doped regions and metal electrodes in Zhou can be fabricated by using the processing sequence of Gardes as a suitable method.
The Zhou – Gardes combination considers lightly-doped regions disposed on both sides of each heavily-doped region abutting a metal electrode: even though Figs. 2g and 2h show only outer lightly-doped regions 118b,120b, it is clear that the implantation step in Fig.s 2f and 2g produce lightly-doped regions on both (left and right) sides of each heavily-doped region 118a,120a. Hence, the Zhou – Gardes combination considers a buffer (lightly-doped) region between the (heavily-doped) contact region 430 and the first portion 436 of the P-N junction diode.
As an aside and relevant comment, it is noted that the buffer (lightly-doped) regions in Gardes are caused by the same effect (implantation that end portions of a mask) as the (optional) buffer regions 329,322 in Fig. 3A of the instant application.
Regarding claim 20, as detailed above for claim 19, the Zhou – Gardes combination considers a (heavily doped) contact region 440 electrically connected to the second portion 446,442,444 of the P-N junction diode; and a buffer (lightly doped) region (according to Gardes) between the (heavily doped) contact region 440 and the second portion 446,442,444 of the P-N junction diode.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
US 2016/0313577 A1
US 10,151,941 B2
US 8,737,772 B2
US 11,686,991 B1
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/ROBERT TAVLYKAEV/Primary Examiner, Art Unit 2896