DETAILED ACTION
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 .
Claim Rejections - 35 USC § 103
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.
Claim(s) 1-6 is/are rejected under 35 U.S.C. 103 as being unpatentable over Han et al. (US 2017/0237234 A1) in view of Torvik (“III-Nitride Semiconductors: Electrical, Structural and Defects Properties” 2000, Pages 17-49, Chapter 2).
Regarding Claim 1, Han (Fig. 5) discloses a method of manufacturing a light emitting element comprising:
preparing a stacked substrate;
disposing a 1-1-th semiconductor layer (510, 515, 560) including a first type of semiconductor “silicon-doped gallium nitride 515; n-type gallium-nitride layer 560) [0053, 0055, 0065] on the stacked substrate;
disposing an intermediate layer (530, 535) on the 1-1-th semiconductor layer;
disposing a 1-2-th semiconductor layer (560) including the first type of semiconductor (“n-type gallium-nitride layer 560” [0065]) on the intermediate layer;
disposing an active layer (565) on the 1-2-th semiconductor layer (560);
disposing a second semiconductor layer (570) including a second type of semiconductor (“a p-type gallium-nitride layer 570) [0065] different from the first type on the active layer (565);
removing at least a portion of each of the 1-1-th semiconductor layer (510, 515, 560), the intermediate layer (530, 535), the 1-2-th semiconductor layer, the active layer 565), and the second semiconductor layer (570) in a direction from the second semiconductor layer toward the 1-2-th semiconductor layer (560); [0065] and
performing an electrochemical etching process on the intermediate layer (530, 535) [0062]
to form a porous structure (“the EC etching converts the heavily doped gallium-nitride layers 535 to porous gallium-nitride layers 550”) in the intermediate layer (530, 535). [0062].
Han does not explicitly disclose a 1-2-th semiconductor layer is doped with first type conductivity type dopant.
However, Han discloses that a 1-1-th semiconductor layer (510, 515) doped with the first type conductivity type dopant (“a conductive layer 515 formed of silicon-doped gallium nitride”). [0053]
Examiner notes that there is limited amount of n-type conductivity dopants (Ex. Si, Ge, Sn) for GaN
Torvik discloses disclosing Si as one of the preferred n-type dopant for GaN material among limited amount of doping materials (“Several column IV elements such as Si, Ge, Sn have been investigated as candidates for n-type doping of GaN” (4.1.2. Si-doping 4.2.2. Si-doping (“Silicon is the n-type dopant of choice for GaN since it effectively incorporates on the gallium site and forms a single shallow donor level.”)
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to modify a light emitting element in Han in view of Torvik such that a 1-2-th semiconductor layer is doped with the first type conductivity type dopant since that the selection of a known material based on its suitability for its intended use supported a prima facie obviousness determination in Sinclair & Carroll Co. v. Interchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945) (See MPEP 2144.07) and in order to effectively incorporates on the gallium site and forms a single shallow donor level. (Torvik)
Regarding Claim 2, Han (Fig. 5) in view of Torvik discloses the method of claim 1, wherein
the disposing of the intermediate layer (535, 530) includes:
disposing a first doped layer doped with a dopant having a first concentration (“heavily-doped gallium-nitride layers of 535”); and
disposing a second doped layer doped with a dopant having a second concentration less than the first concentration. (“moderately-doped gallium-nitride layers 530”) [0054]
Regarding Claim 3, Han (Fig. 5) in view of Torvik discloses the method of claim 2, wherein
the first doped layer (535) has a first thickness (T1) that satisfies Equation 1, and the second doped layer (530) has a second thickness (T2) [0057, 0059]
Han in view of Torvik does not explicitly disclose that the first doped layer (535) has a first thickness (T1) that satisfies Equation 1, and the second doped layer (530) has a second thickness (T2) that satisfies Equation 2, wherein
Equation 1 is defined as follows:
PNG
media_image1.png
58
73
media_image1.png
Greyscale
wherein
n1 is a refractive index of the first doped layer, λ is a wavelength [nm] of light emitted from the active layer, m=2h1−1, and h1 is an integer greater than or equal to 1, and Equation 2 is defined as follows
:
PNG
media_image2.png
57
73
media_image2.png
Greyscale
wherein
n2 is a refractive index of the second doped layer, λ is the wavelength [nm] of the light emitted from the active layer, m=2h2−1, and h2 is an integer greater than or equal to 1.
However, Han disclosing varying thicknesses for the first doped layer (535) has a and the second doped layer (530) [0056-0059].
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to modify the light emitting element in Han in view of Torvik such that the first doped layer (535) has a first thickness (T1) that satisfies Equation 1, and the second doped layer (530) has a second thickness (T2) that satisfies Equation 2, wherein Equation 1 is defined as follows:
PNG
media_image1.png
58
73
media_image1.png
Greyscale
wherein n1 is a refractive index of the first doped layer, λ is a wavelength [nm] of light emitted from the active layer, m=2h1−1, and h1 is an integer greater than or equal to 1, and Equation 2 is defined as follows
:
PNG
media_image2.png
57
73
media_image2.png
Greyscale
wherein n2 is a refractive index of the second doped layer, λ is the wavelength [nm] of the light emitted from the active layer, m=2h2−1, and h2 is an integer greater than or equal to 1 since it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. In re Boesch, 617 F.2d 272, 276 (CCPA 1980) and to have DBR that correspond to approximately ¼ wavelength of the VCSEL's designed operating wavelength [0057, 0058]
Regarding Claim 4, Han (Fig. 5) in view of Torvik discloses the method of claim 2, wherein the first doped layer and the second doped layer are formed by epitaxial growth. [0055]
Regarding Claim 5, Han (Fig. 5) in view of Torvik discloses the method of claim 2, wherein the electrochemical etching process is performed through the side surface of the intermediate layer and is selectively performed on the first doped layer. [“lateral etching”, 0046, 0062]
Regarding Claim 6, Han (Fig. 5) in view of Torvik discloses the method of claim 1, wherein
a thickness of the intermediate layer (530, 535) is in a range.
Han in view of Torvik does not explicitly disclose a thickness of the intermediate layer is in a range of about 1 μm to about 2 μm.
However, Han discloses varying thickness of the intermediate layer (530, 535) based on a desired VCSEL's designed operating wavelength, having thickness of each layer 530 between approximately 40 nm and approximately 60 nm or an odd number multiple thereof and thickness of each layer 535 the thicknesses t.sub.2 of the heavily-doped gallium-nitride layers 535 may be selected such that after being etched to form porous layers, the resulting thickness of each layer corresponds to approximately ¼ wavelength (or an odd-number multiple thereof) of the VCSEL's designed lasing wavelength [0056-0059] and further discloses there may be 6 to 20 layer pairs of undoped or moderately-doped and heavily-doped gallium-nitride layers in a DBR structure [0054]
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to modify the light emitting element in Han in view of Torvik such that a thickness of the intermediate layer is in a range of about 1 μm to about 2 μm in order to have DBR thickness that correspond to approximately ¼ wavelength of the VCSEL's designed operating wavelength [0057, 0058] and since it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. In re Boesch, 617 F.2d 272, 276 (CCPA 1980)
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Han et al. (US 20160197151 A1) and Wu et al. (US 20140167097 A1) and Kim (US 20170005242 A1) discloses vertical etching of LED and lateral porosification gallium-nitride layer by electrochemical etching
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/DMITRIY YEMELYANOV/Examiner, Art Unit 2891
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