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 .
Note: For ALL the claims, the Examiner notes the definition of a superlattice as known to a person of ordinary skill in the art includes quantum wells and barriers caused by alternating different bandgaps, see Google search below (see PTO-892):
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Lee et al. (US 20130002141 A1) is provided as evidence that a person of ordinary skill in the art is aware that a structure designed for use in an LED can also be used for detection, see Lee paragraph 0013 “A reverse biased LED can act as a photodiode”.
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claim 1-16 rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the enablement requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to enable one skilled in the art to which it pertains, or with which it is most nearly connected, to make and/or use the invention.
See Claim 1 recites that j is 2 or more, yet see claim 8 “wherein the first gallium arsenide layer and the third gallium arsenide layer each have a thickness of 0.2 nm to 1.5 nm, and the second gallium arsenide layer has a thickness of 0 nm to 1.2 nm”, the Examiner notes that a GaAs monolayer is about 2.8A thick and thus for j= 2 the thickness has to be at least 5.6A similary j-1 =2-1 = 1 monolayer and thus the second gallium arsenide layer has to be at least 2.8A . The Examiner notes that these numbers j, k, m, n have been corrected in response to a previous 112 rejection and at this point the Examiner believes that the Applicant was not in "possession" of the claimed invention at the time of filing and that the invention is being corrected by the Examiner, thus 112 enablement rejection is provided.
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.
The factual inquiries 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.
Claim(s) 1-16 is/are rejected under 35 U.S.C. 103 as being unpatentable over Svensson (US 20080179589 A1) in view of Jewell et al. (US 5719895 A) hereafter referred to as Jewell. Ma et al. (US 20190356114 A1) hereafter referred to as Ma is provided as evidence of the meaning of superlattice.
In regard to claim 1 Svensson teaches [“FIG. 2 is an embodiment of a p-on-n detector utilizing a Gallium Antimonide (GaSb) substrate”] a semiconductor photodetector comprising:
an substrate [“Gallium Antimonide (GaSb) substrate”];
a first group lIl-V semiconductor layer [“n-type GaSb contact layer 204”] of a first conductivity type stacked on the substrate;
a second group llI-V semiconductor layer [“p-type GaSb (or superlattice) contact layer 208”] of a second conductivity type; and
an optical absorption layer [“An absorbing, antimonide-based superlattice 206 may be applied to a portion of the contact layer 204”] disposed between the first group lII-V semiconductor layer and the second group llI-V semiconductor layer in a first direction, wherein the optical absorption layer includes a plurality of unit structures [this is part of the definition of a superlattice, see evidence of Ma, see Abstract “superlattice structures include alternating quantum barrier layers and quantum well layers” see Fig. 4B “FIG. 4B shows the band diagram, including both the valance and conduction bands, for an active region of a QCL that comprises a superlattice structure having four amorphous inorganic barrier layers and three single-crystalline semiconductor quantum wells” see in Fig. 4B what happens to the band structure of a superlattice by application of voltage, “During operation electrons are injected into a higher energy level (E3) in the active region. These electrons then undergo an intersubband radiative transition to a lower energy level (E2)”:
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] stacked in the first direction,
but does not teach that the substrate is indium phosphide,
each of the plurality of unit structures includes:
a laminate comprising an electron well, and
a gallium arsenide antimonide layer comprising one or more electron barriers,
the laminate includes a first gallium arsenide layer including j gallium arsenide monolayers, a first indium arsenide layer including m indium arsenide monolayers, k stacked structures, and a second gallium arsenide layer including (j - 1) gallium arsenide monolayers, the second gallium arsenide layer, the k stacked structures, the first indium arsenide layer, and the first gallium arsenide layer are stacked in this order in the first direction, each of the k stacked structures includes a third gallium arsenide layer including n gallium arsenide monolayers and a second indium arsenide layer including m indium arsenide monolayers, and in each of the k stacked structures, the second indium arsenide layer and the third gallium arsenide layer are stacked in this order in the first direction, the gallium arsenide antimonide layer is in direct contact with the first gallium arsenide layer or the first indium arsenide layer, and jis an integer of 2 or more, and k is an integer of 0 or more.
The Examiner notes that the remainder of claim 1 above is just a description of a large superlattice comprising stacked units, each comprising AlAs/GaAs as the repeating period with GaAs being on either end and having p doped GaAsSb separating spacers (which can be described as “electron barrier”) and as can be seen below this is exactly what Jewell teaches and the Examiner notes that the integers j, k, m, n are merely a way to describe the structure of Jewell and have been corrected in 112 amendments and these integers have no novelty for the purpose of allowance, and as Jewell teaches InP substrate is common in the art.
The Examiner notes that GaSb is a III-V material, part of the III-V family of materials, see Jewell teaches see Fig. 11 see the different materials connected by using Vegard's law, see lattice constant on the X axis allows material choice based on bandgap energy, since the claim utilizes GaAsSb the Examiner notes the line for GaAsSb in Fig. 11, these material choices for wells and barriers are very common in the art.
See Jewell teaches a [see Fig. 8 see column 32, “Semiconductor structure 50 illustrates the use of superlattice layers” see Background column 1 line 26, see column 6 “The present invention relates generally to semiconductor light sources such as LEDs and VCSELs” “It is therefore an object of the present invention to provide an active region having a quantum well structure which may be utilized in lasers” “Layers 54 and 70 may be of the same material or may be constructed of different semiconductor material or they may have the same basic composition but be of opposite conductivity types”] semiconductor superlattice structure comprising:
an indium phosphide substrate [“Device 50 is grown on a GaAs substrate 52. It should be appreciated that the substrate may also be InP as discussed below” “When present, tensile strained layers 56, 64, and/or 68 preferably comprise GaAs.sub.1-z P.sub.z with 0.ltoreq.z.ltoreq.1.0, if substrate 52 comprises GaAs, or In.sub.y Ga.sub.1-y As with 0.53.ltoreq.y.ltoreq.1.0 if substrate 52 comprises InP”];
a first semiconductor layer [54 “confining layer 54 is grown on substrate 52 by an epitaxial process”] of a first conductivity type stacked on [the Examiner notes that “stacked on” simply means on ] the indium phosphide substrate;
a second semiconductor layer [“a confining layer 70 is grown by an epitaxial process” “Layers 54 and 70 may be of the same material or may be constructed of different semiconductor material or they may have the same basic composition but be of opposite conductivity types”] of a second conductivity type; and
an optical absorption layer [“strain compensated superlattice”, inherently it is an absorption layer] disposed between the first semiconductor layer and the second semiconductor layer in a first direction,
wherein the optical absorption layer includes a plurality [“In this example, a multiple quantum well structure is illustrated as may be seen from second quantum well 66. It should be appreciated that quantum well 66 need not be present and that a functional device contemplated by the invention may have only one quantum well. The advantage of having multiple quantum wells is that for a given electron-hole density, the optical gain is increased. For convenience, quantum well 66 is constructed in a similar manner as quantum well 58”] of unit structures stacked in the first direction,
each of the plurality of unit structures includes a laminate comprising an electron well [see that in the superlattice, due to the higher band gap of the barrier than the well, when the Fermi level is flat, the conduction band has an “electron well” usually called a “quantum well”] and
a gallium arsenide antimonide layer [ “When present, tensile strained layers 56, 64, and/or 68 preferably comprise GaAs.sub.1-z P.sub.z with 0.ltoreq.z.ltoreq.1.0, if substrate 52 comprises GaAs, or In.sub.y Ga.sub.1-y As with 0.53.ltoreq.y.ltoreq.1.0 if substrate 52 comprises InP” “result of these similarites means that from a materials standpoint, In and Sb may be "interchanged" nearly equally. For example, the alloys In.sub.0.5 Ga.sub.0.5 As and In.sub.0.4 Ga.sub.0.6 As.sub.0.9 Sb.sub.0.1 are expected to be roughly equivalent in terms of lattice constant and in peak transition energy. Since the InGaAs line lies below the GaAsSb line, InGaAs has a lower peak transition energy than does GaAsSb having the same lattice constant. Therefore, from a strain-bandgap viewpoint, InGaAs is slightly preferred over GaAsSb for long-wavelength emission on GaAs substrates. InGaAs is also preferred due to more chemical characteristics. Despite the preference for InGaAs, the present invention includes the use of Sb-containing compounds. In the context of this application, statements regarding In.sub.y Ga.sub.1-y As where y is .gtoreq.0.5 re ment to include In.sub.y Ga.sub.1-y As.sub.1-w Sb.sub.w with (y+w).gtoreq.0.5” “While we have focused the discussion of the variation of In concentration, it should be appreciated that other group III semiconductor materials may be utilized. For example, the In concentration may be reduced if sufficient Sb is introduced. Nominally, each percent of Sb is almost as effective as In at reducing peak transition energy and it increases the lattice constant by about the same amount”, see “Layers 56 and 64 may be of the same material or may be constructed of different semiconductor material or they may have the same basic composition but be of opposite conductivity types” see that with p-type doping the valence band is closer to the Fermi level, thus the conduction band forms an “electron barrier”] comprising one or more electron barriers,
the laminate includes
a first gallium arsenide layer [“GaAs(N) layer 60 having a thickness of .about.3 .ANG., i.e., one monolayer” “It is to be appreciated that the possible inclusion of nitrogen in GaAs(N) layers 60 may not perform a critical function. Rather, it may simplify the process to keep the nitrogen flowing throughout the growth of superlattice quantum well 58 due to the extreme thinness of layers 60 and 62” , see other examples such as “Yet another example is the aperiodic superlattice (InAs).sub.2 (GaAs).sub.2 (InAs).sub.4 (GaAs).sub.2 (InAs).sub.2 bounded by GaAs on both sides”, i.e. the GaAs is 2 monolayers] including j gallium arsenide monolayers,
a first indium arsenide layer [“InAs(N) layer 62 having a thickness of .about.6 .ANG., i.e., two monolayers in this example”, in this case m is 2] including m indium arsenide monolayers,
k stacked structures [see that 58 comprises 60 at both ends and in the middle with 62 in between “Thus, one period of the superlattice structure 58 is formed. This process is repeated. FIG. 8 illustrates three periods which terminated in a GaAs(N) layer 60. This is merely illustrative of one superlattice structure which closely resembles the superlattice illustrated in FIG. 4a. For other superlattice structures, please refer to FIGS. 4a through 4d”, thus see below k “integer of 0 or more” is satisfied], each of the k stacked structures includes a third gallium arsenide layer [“GaAs(N) layer 60 having a thickness of .about.3 .ANG., i.e., one monolayer” so in this case n is 1] including n gallium arsenide monolayers and a second indium arsenide layer [“InAs(N) layer 62 having a thickness of .about.6 .ANG., i.e., two monolayers in this example”, in this case m is 2] including m indium arsenide monolayers, and
a second gallium arsenide layer [see other examples such as “Yet another example is the aperiodic superlattice (InAs).sub.2 (GaAs).sub.2 (InAs).sub.4 (GaAs).sub.2 (InAs).sub.2 bounded by GaAs on both sides”, GaAs can be any number of layers] including (j - 1) gallium arsenide monolayers,
the second gallium arsenide layer, the k stacked structures, the first indium arsenide layer, and the first gallium arsenide layer are stacked in this order in the first direction,
and in each of the k stacked structures, the second indium arsenide layer and the third gallium arsenide layer are stacked [see that 58 comprises 60 at both ends and in the middle with 62 in between] in this order in the first direction,
the gallium arsenide antimonide layer is in direct contact [see Jewell Fig. 8 56 and 64 and 68 touch 60 which is GaAs] with the first gallium arsenide layer or the first indium arsenide layer, and
j [see above3, see other examples such as “Yet another example is the aperiodic superlattice (InAs).sub.2 (GaAs).sub.2 (InAs).sub.4 (GaAs).sub.2 (InAs).sub.2 bounded by GaAs on both sides”, i.e. the GaAs is 2 monolayers] is an integer of 2 or more, and k [see above k is satisfied] is an integer of 0 or more.
Thus, it 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 to modify Svensson to include that the substrate is indium phosphide, each of the plurality of unit structures includes: a laminate comprising an electron well, and a gallium arsenide antimonide layer comprising one or more electron barriers, the laminate includes a first gallium arsenide layer including j gallium arsenide monolayers, a first indium arsenide layer including m indium arsenide monolayers, k stacked structures, and a second gallium arsenide layer including (j - 1) gallium arsenide monolayers, the second gallium arsenide layer, the k stacked structures, the first indium arsenide layer, and the first gallium arsenide layer are stacked in this order in the first direction, each of the k stacked structures includes a third gallium arsenide layer including n gallium arsenide monolayers and a second indium arsenide layer including m indium arsenide monolayers, and in each of the k stacked structures, the second indium arsenide layer and the third gallium arsenide layer are stacked in this order in the first direction, the gallium arsenide antimonide layer is in direct contact with the first gallium arsenide layer or the first indium arsenide layer, and j is an integer of 2 or more, and k is an integer of 0 or more.
Thus it would be obvious to combine the references to arrive at the claimed invention.
The motivation is that Indium Phosphide substrate is a commonly used substrate known to give excellent results for optical devices and that the superlattice of Jewell is versatile with many options (i.e. j, k, m, n as described by the Applicant) to make athick superlattice to best interact with light.
The Examiner is also adding a case law rejection in addition, see that the optical behavior of the superlattice is measurable and adjusting layer thicknesses affects the effective bandgap of the superlattice, It 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 to use “j, k, m, n as described in the claim ”, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or working ranges involves only routine skill in the art. In re Aller, 105 USPQ 233
In regard to claim 2 Svensson and Jewell as combined teaches wherein the first group III-V semiconductor layer [i.e. 54 see Fig. 8] is disposed between [see Fig. 8] the indium phosphide substrate and the optical absorption layer in the first direction,
but does not state and 0.95 < y + r < 1.05 is satisfied, where y is an arsenic fraction in the gallium arsenide antimonide layer, and r is a ratio of the number of gallium arsenide monolayers to a sum of the number of gallium arsenide monolayers and the number of indium arsenide monolayers in the laminate.
See that for the example in claim 1, “GaAs(N) layer 60 having a thickness of .about.3 .ANG., i.e., one monolayer” “InAs(N) layer 62 having a thickness of .about.6 .ANG., i.e., two monolayers in this example”, thus r = 0.33, and the description for antimony, see “When present, tensile strained layers 56, 64, and/or 68 preferably comprise GaAs.sub.1-z P.sub.z with 0.ltoreq.z.ltoreq.1.0, if substrate 52 comprises GaAs, or In.sub.y Ga.sub.1-y As with 0.53.ltoreq.y.ltoreq.1.0 if substrate 52 comprises InP” “result of these similarites means that from a materials standpoint, In and Sb may be "interchanged" nearly equally. For example, the alloys In.sub.0.5 Ga.sub.0.5 As and In.sub.0.4 Ga.sub.0.6 As.sub.0.9 Sb.sub.0.1 are expected to be roughly equivalent in terms of lattice constant and in peak transition energy. Since the InGaAs line lies below the GaAsSb line, InGaAs has a lower peak transition energy than does GaAsSb having the same lattice constant. Therefore, from a strain-bandgap viewpoint, InGaAs is slightly preferred over GaAsSb for long-wavelength emission on GaAs substrates. InGaAs is also preferred due to more chemical characteristics. Despite the preference for InGaAs, the present invention includes the use of Sb-containing compounds. In the context of this application, statements regarding In.sub.y Ga.sub.1-y As where y is .gtoreq.0.5 re ment to include In.sub.y Ga.sub.1-y As.sub.1-w Sb.sub.w with (y+w).gtoreq.0.5” “While we have focused the discussion of the variation of In concentration, it should be appreciated that other group III semiconductor materials may be utilized. For example, the In concentration may be reduced if sufficient Sb is introduced. Nominally, each percent of Sb is almost as effective as In at reducing peak transition energy and it increases the lattice constant by about the same amount”, thus Jewell teaches a large range for arsenic fraction.
It 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 to use “and 0.95 < y + r < 1.05 is satisfied, where y is an arsenic fraction in the gallium arsenide antimonide layer, and r is a ratio of the number of gallium arsenide monolayers to a sum of the number of gallium arsenide monolayers and the number of indium arsenide monolayers in the laminate ”, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or working ranges involves only routine skill in the art. In re Aller, 105 USPQ 233
In regard to claim 3 Svensson and Jewell as combined teaches [see claim 1 above, in this case j is 1, in this case m is 2, in this case n is 1] wherein j, m, and n are each 6 or less.
In regard to claim 4 Svensson and Jewell as combined teaches [see claim 1 above, see Fig. 8 see “FIG. 8 illustrates three periods which terminated in a GaAs(N) layer 60. This is merely illustrative of one superlattice structure which closely resembles the superlattice illustrated in FIG. 4a”] wherein k is 1 or more.
In regard to claim 5 Svensson and Jewell as combined teaches [see claim 1 above, see Fig. 8 see “FIG. 8 illustrates three periods which terminated in a GaAs(N) layer 60. This is merely illustrative of one superlattice structure which closely resembles the superlattice illustrated in FIG. 4a”] wherein k is 13 or less.
In regard to claim 6 Svensson and Jewell as combined teaches wherein [“When present, tensile strained layers 56, 64, and/or 68 preferably comprise GaAs.sub.1-z P.sub.z with 0.ltoreq.z.ltoreq.1.0, if substrate 52 comprises GaAs, or In.sub.y Ga.sub.1-y As with 0.53.ltoreq.y.ltoreq.1.0 if substrate 52 comprises InP” “result of these similarites means that from a materials standpoint, In and Sb may be "interchanged" nearly equally. For example, the alloys In.sub.0.5 Ga.sub.0.5 As and In.sub.0.4 Ga.sub.0.6 As.sub.0.9 Sb.sub.0.1 are expected to be roughly equivalent in terms of lattice constant and in peak transition energy. Since the InGaAs line lies below the GaAsSb line, InGaAs has a lower peak transition energy than does GaAsSb having the same lattice constant. Therefore, from a strain-bandgap viewpoint, InGaAs is slightly preferred over GaAsSb for long-wavelength emission on GaAs substrates. InGaAs is also preferred due to more chemical characteristics. Despite the preference for InGaAs, the present invention includes the use of Sb-containing compounds. In the context of this application, statements regarding In.sub.y Ga.sub.1-y As where y is .gtoreq.0.5 re ment to include In.sub.y Ga.sub.1-y As.sub.1-w Sb.sub.w with (y+w).gtoreq.0.5” “While we have focused the discussion of the variation of In concentration, it should be appreciated that other group III semiconductor materials may be utilized. For example, the In concentration may be reduced if sufficient Sb is introduced. Nominally, each percent of Sb is almost as effective as In at reducing peak transition energy and it increases the lattice constant by about the same amount”, see that Jewell discloses any portion of As can be replaced by Sb for obtaining the same results] the gallium arsenide antimonide layer has an arsenic fraction of 0.3 to 0.7.
In regard to claim 7 Svensson and Jewell as combined teaches wherein the gallium arsenide antimonide layer includes [“tensile strained layer 56 may be grown by an epitaxial process such as MBE, MOCVD or MOMBE at a temperature of 500.degree. C. for a period of 0.3 minutes. This results in tensile strained layer 56 having a thickness of 50 .ANG.”, see similarly 64, and/or 68, see that 50 angstrom of monolayers satisfies the claim limitation, since each monolayer is on the order of ~3 angstrom] p gallium arsenide antimonide monolayers, and p is an integer of 10 to 26.
In regard to claim 8 [see 112 rejection] Svensson and Jewell as combined teaches wherein [see claim 1, see combination, see that Jewell teaches that the GaAs monolayers can be of differing thicknesses, see also case law rejection adjusting these thickness is not novel] the first gallium arsenide layer and the third gallium arsenide layer each have a thickness of 0.2 nm to 1.5 nm, and the second gallium arsenide layer has a thickness of 0 nm to 1.2 nm.
In regard to claim 9 Svensson and Jewell as combined teaches wherein the first indium arsenide layer and the second indium arsenide layer each have [“InAs(N) layer 62 having a thickness of .about.6 .ANG., i.e., two monolayers in this example”] a thickness of 0.2 nm to 1.6 nm.
In regard to claim 10 Svensson and Jewell as combined teaches wherein the gallium arsenide antimonide layer has a thickness [“tensile strained layer 56 may be grown by an epitaxial process such as MBE, MOCVD or MOMBE at a temperature of 500.degree. C. for a period of 0.3 minutes. This results in tensile strained layer 56 having a thickness of 50 .ANG.”, see similarly 64, and/or 68] of 2.5 nm to 6.3 nm.
In regard to claim 11 Svensson and Jewell as combined does not specifically teach wherein the number of the plurality of unit structures comprises a value at or between 100 to 500.
See that the teaching of Jewell is to make a thicker superlattice by stacking them, see that a thicker superlattice layer will interact more with light, It 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 to use “wherein the number of the plurality of unit structures comprises a value at or between 100 to 500 ”, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or working ranges involves only routine skill in the art. In re Aller, 105 USPQ 233
In regard to claim 12 Svensson and Jewell as combined [see claim 1 rejection see the Jewell Fig. 8, see between GaAsSb layers], wherein the electron well is between first and second electron barriers of the one or more electron barriers.
In regard to claim 13 Svensson and Jewell as combined [see claim 1 rejection see the Jewell Fig. 8, see the InAs/GaAs layers between GaAsSb layers, there is GaAs at each end], wherein the energy at a first interface between the first electron barrier and the electron well is a same energy at a second interface between the second electron barrier and the electron well.
In regard to claim 14 Svensson and Jewell as combined [see claim 1 rejection see the Jewell Fig. 8, see the InAs/GaAs layers between GaAsSb layers, there is GaAs at each end and InAs between each GaAs] wherein the electron well comprises a symmetric atomic arrangement with respect to a center position of the electron well layer in a first direction.
In regard to claim 15 Svensson and Jewell as combined does not specifically teach wherein the electron well comprises gallium indium arsenide.
However see Jewell Fig. 3, Fig. 11 see that bandgap can be adjusted using InGaAs composition.
Thus, it 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 to modify Svensson to include wherein the electron well comprises gallium indium arsenide.
Thus it would be obvious to combine the references to arrive at the claimed invention.
The motivation is this is standard bandgap adjustment to obtain a desired bandgap rather than relying only on InAs or GaAs.
In regard to claim 16 Svensson and Jewell as combined teaches [see claim 1 see Jewell structure, see the bandgap of the materials, this is due to the effective bandgap, see Einstein equation E= hv] wherein a wavelength of an optical absorption edge of the optical absorption layer comprises 2.45 μm or more.
Response to Arguments
Applicant's arguments filed 4/20/2026 have been fully considered but they are not persuasive.
On page 7, 8, 9 the Applicant argues “specification discloses that "GaAsySb1-y layer L1 may function as an electron barrier layer or a hole well layer. Laminate LM may function as an electron well layer or a hole barrier layer." This structural relationship between the laminate and the gallium arsenide antimonide layer is a critical feature of the claimed semiconductor photodetector. According to the specification, "laminate LM in each unit structure U1 functions as the electron well layer. In semiconductor photodetector 10, the spectrum of the optical- absorption coefficient has lower dependence on the polarization direction of incident light L than in the case where the electron well layer in each unit structure is formed only of the GalnAs layer. This is considered to be because the atomic arrangement has symmetry with respect to the center position of the electron well layer in first direction D1." (As-Filed Specification, paragraph [0053]). Further, the recited GaAsSb layer being in direct contact with the first GaAs layer or the first InAs layer is essential for reducing polarization dependence of the optical absorption layer in the present application.
Jewell discloses providing InyGa1.yAs1-wSbw, where (y+w)>0.5, as a strain compensation layer on a GaAs substrate (column 31, line 59). Jewell also discloses providing InyGa1-yAs (0.53<y<1.0) on an InP substrate (column 33). Jewell does not teach a semiconductor photodetector with the claimed structure because Jewell is directed to light emitting devices (LEDsNCSELs), not photodetectors. Jewell also does not teach a semiconductor photodetector with the claimed structure because Jewell is devoid of any description or suggestion of polarization dependence, let alone the recited GaAsSb layer being in direct contact with the first GaAs layer or the first InAs layer.
Svensson does not teach or suggest a semiconductor photodetector having an optical absorption layer with unit structures that each include both a laminate and a gallium arsenide antimonide layer as claimed. Svensson merely discloses a type II superlattice detector with structure comprising first and second gallium arsenide layers with (j) and (j-1) monolayers respectively, indium arsenide layers, and k stacked structures arranged in the claimed order, combined with a gallium arsenide antimonide (GaAsSb) layer in each unit structure. That is, Svensson discloses providing a GaSb/InAs superlattice layer, an InAs layer on a GaAs substrate (Svensson FIGS. 2). Svensson's structure is devoid of a structure including, on an InP substrate, a light absorption layer having a first GaAs layer in direct contact with a GaAsSb layer, as recited in amended claim 1. Svensson also does not teach a semiconductor photodetector with the claimed structure because Svensson is devoid of any description or suggestion of polarization dependence, let alone the recited GaAsSb layer being in direct contact with the first GaAs layer or the first InAs layer. Moreover, there is no motivation to combine Jewell and Svensson for the purpose of reducing polarization dependence.
Further, the cited references do not teach or suggest a laminate as an electron well in combination with a gallium arsenide antimonide layer as an electron barrier. The Office Action maps Jewell's tensile strained layers 56, 64, and 68 to the claimed gallium arsenide antimonide layer. However, Jewell explicitly teaches that these tensile strained layers are for strain compensation purposes, not as electron barrier layers. Jewell states that "tensile strained layer 56 may be grown" and "if the technique of strain compensation is utilized, the tensile strained layer 56 will be present." The structural relationship recited by amended claim 1-"each of the plurality of unit structures includes: a laminate comprising an electron well, and a gallium arsenide antimonide layer comprising one or more electron barriers"-defines a type-Il superlattice structure with specific band alignment properties. Jewell's superlattice structure (Fig. 8) with GaAs(N) layers 60 and InAs(N) layers 62 is designed for light emission in LEDs and VCSELs, not for photodetection with electron well/electron barriers. Svensson teaches infrared detector structures with GaSb/InAs superlattices but does not cure the deficiencies of Jewell. Svensson's superlattice structures do not include a laminate as an electron well combined with a gallium arsenide antimonide layer as an electron barrier as recited by amended claim 1. The combination of Jewell and Svensson fails to teach or suggest the specific structural relationship between the laminate and the gallium arsenide antimonide layer as now recited by amended claim 1. Additionally, the specification explains that this specific structure provides the technical advantage that "the optical-absorption coefficient when the polarization direction is the [110] direction is almost the same as the optical-absorption coefficient when the polarization direction is the [1-10] direction. In the first experiment, the spectrum of the optical-absorption coefficient has low dependence on the polarization direction of incident light." This technical advantage arises from the specific electron well/electron barrier structure recited by amended claim 1, which is not taught or suggested by the cited references”.
The Examiner responds that see amended rejection above, this has to do with doping of the GaAsSb layer and for p type the valence band is closer to the Fermi level and the conduction band rises and the GaAsSb layers in Jewell with the InAs/GaAs periods in between form the electron well, this claim limitation is just a description of the Jewell reference Fig. 8 and is taught by Jewell. The Examiner notes that the structural limitations of the claims are taught by the combination of Svensson and Jewell and the material properties are known to any person of ordinary skill in the art. The Examiner responds that simply finding another way to describe the known properties of prior art Jewell is not novel and cannot be a grounds for allowance, and intended use is not novel.
On page 7, 8, 9 the Applicant argues “Additionally, Applicant notes that U.S. Publication Number 2013/0002141 ("Lee") was listed in the Office Action as evidence without establishing a rejection thereupon. The Office Action's reliance on Lee's statement that 'a reverse biased LED can act as a photodiode' is insufficient to establish obviousness since Lee relates to LED driving circuits for lighting applications, not IlIl-V semiconductor superlattice structures for infrared detection, and there is no motivation to combine these disparate technologies, alternating InAs/GaSb layers for infrared detection, let alone the specific laminate as claimed. Applicant also rejects any further taking of Official Notice (whether expressly stated or ve3illed under the term inherency) and request that any further rejection properly cite and assert a valid reference under 102/103”.
The Examiner responds that no matter what the Applicant argues, the Applicant cannot change the material properties of the materials or the band diagram of the structure of Svensson and Jewell, the reverse biasing of a diode to operate as a photodetector is well known in the art and the Examiner stands by the statement of Lee that “A reverse biased LED can act as a photodiode” and the argument of the Applicant that the structure of Jewell will not absorb light is incorrect and the Examiner asks the Applicant to show a band diagram supporting your argument, the Examiner notes that the Applicant does not currently do so perhaps because the Applicant understands that the structure of Jewell is identical to what is claimed by the Applicant and that such an admission would invalidate any claim to novelty of the instant Application and thus allowance.
Conclusion
Lee et al. (US 20130002141 A1) hereafter referred to as Lee is provided as evidence that a person of ordinary skill in the art is aware that a structure designed for use in an LED can also be used for detection, see Lee paragraph 0013 “A reverse biased LED can act as a photodiode”.
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/SITARAMARAO S YECHURI/ Primary Examiner, Art Unit 2893
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