DETAILED ACTION
This Office Action is in response to the application filed on 24 August 2023.
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 § 102
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 (i.e., changing from AIA to pre-AIA ) 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.
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)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claim(s) 1-10 and 12-19 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Beam et al. (US 2019/0237570 A1; hereinafter Beam).
In regards to claim 1, Beam teaches a High-Electron-Mobility-Transistor, HEMT, comprising:
a first layer (56) which comprises a first material made of a first nitride compound, wherein the first nitride compound comprises a group III element (GaN) [0033],
a second layer (60) which comprises a second material made of a second nitride compound, wherein the second nitride compound comprises a group III element (AlN) [0033],
wherein a main surface of the second layer is arranged opposite a main surface of the first layer such that a charge zone (2DEG) forms along the main surface of the first layer, which provides a conduction channel in an enabled state of the HEMT (fig. 8: e.g. bottom surface of (60) is opposite top surface of (56)) [0026],
a gate electrode (68) [0033], which is arranged opposite the second layer (read as on the opposite side of the second layer from the first layer), at least in regions, such that the second layer is arranged between the first layer and the gate electrode (fig. 8: e.g. (60) is between (56) and (68)),
a third layer (64) [0033], which is arranged between the gate electrode and the second layer (fig. 8: (64) is between (68) and (60))), wherein the third layer comprises a ferroelectric third material made of a third nitride compound, or a ferroelectric third material made of an oxide compound which comprises zinc, the third material comprising a transition metal (fig. 8) ([0033]: ScyAlzGa1-y-zN).
In regards to claim 2, Beam teaches the limitations discussed above in addressing claim 1. Beam further teaches the limitations wherein the first material comprises a wurtzite crystal structure, and wherein the second material comprises a wurtzite crystal structure, and/or wherein the third material (ScyAlzGa1-y-zN) comprises a wurtzite crystal structure (fig. 9) [0033]. Teaching reference Soltani et al. (US 2019/0346624 A1; hereinafter Soltani) teaches that ScAlGaN and alloys thereof have wurtzite structures [0064].
In regards to claim 3, Beam teaches the limitations discussed above in addressing claim 2. Beam further teaches the limitations wherein a coercivity of the third material is less than a coercivity of the second material (fig. 8) ([0033]: taught because (64) is made of a ferroelectric material).
In regards to claim 4, Beam teaches the limitations discussed above in addressing claim 1. Beam further teaches the limitations wherein a proportion of the transition metal in the third layer is higher than a proportion of a transition metal in the second layer (fig. 9) ([0033]: ScyAlzGa1-y-zN).
In regards to claim 5, Beam teaches the limitations discussed above in addressing claim 1. Beam further teaches the limitations wherein the third material comprises a tensile stress [0003].
In regards to claim 6, Beam teaches the limitations discussed above in addressing claim 1. Beam further teaches the limitations wherein the transition metal is Sc, Nb, Ti or Y (fig. 9) ([0033]: ScyAlzGa1-y-zN).
In regards to claim 7, Beam teaches the limitations discussed above in addressing claim 1. Beam further teaches the limitations wherein the third material is made of the third nitride compound, and the third nitride compound comprises one or more group III elements, and wherein a stoichiometric proportion of the transition metal in the third material is between 10% and 50% of a total stoichiometric proportion of the one or more group III elements and the transition metal in the third material (fig. 9) ([0033]: ScyAlzGa1-y-zN).
In regards to claim 8, Beam teaches the limitations discussed above in addressing claim 1. Beam further teaches the limitations wherein the gate electrode and the third layer are part of a gate structure which is arranged so as to be opposite the second layer, in regions (e.g. fig. 8: (64) is adjacent to gate contact (68)).
In regards to claim 9, Beam teaches the limitations discussed above in addressing claim 1. Beam further teaches the limitations further comprising a fourth layer (62) which is arranged between the second layer and the third layer (fig. 8: (62) is between (60) and (64)), wherein the fourth layer comprises an electrically conductive material [0034].
In regards to claim 10, Beam teaches the limitations discussed above in addressing claim 9. Beam further teaches the limitations wherein a capacitance between the fourth layer and the charge zone is greater than a capacitance between the fourth layer and the gate electrode (fig. 8) ([0033]: taught because (64) is made of a ferroelectric material).
In regards to claim 12, Beam teaches the limitations discussed above in addressing claim 1. Beam further teaches the limitations wherein the combination of the first material (GaN) and the second material (AlN) is one of AlGaN / GaN, AlScN / GaN, AlN/GaN and AlScN / GaScN (fig. 8) [0033].
In regards to claim 13, Beam teaches the limitations discussed above in addressing claim 1. Beam further teaches the limitations wherein a polarization state of the third material can be set by applying a voltage to the gate electrode, and wherein a threshold voltage of the HEMT, at which a conduction channel through the charge zone changes between an enabled state and a disabled state, is dependent on the polarization state of the third material (fig. 8) ([0033]: taught because (64) is made of a ferroelectric material).
In regards to claim 14, Beam teaches the limitations discussed above in addressing claim 13. Beam further teaches the limitations wherein the third material comprises a first polarization state, wherein the threshold voltage is positive when the third material is in the first polarization state and/or wherein the third material comprises a second polarization state, wherein the threshold voltage is negative when the third material is in the second polarization state (fig. 8) ([0033]: taught because (64) is made of a ferroelectric material).
In regards to claim 15, Beam teaches the limitations discussed above in addressing claim 13. Beam further teaches the limitations
wherein the gate electrode (68) is arranged in a gate electrode region such that the polarization state of the third material in a first region of the third layer, opposite the gate electrode region, can be set by applying a voltage to the gate electrode, wherein the third layer further comprises a second region that is different from the first region (fig. 8) ([0033]: taught because (64) is made of a ferroelectric material), and
wherein the third material of the second region of the third layer is in a polarization state for which a charge zone region of the charge zone that is opposite the second region is in a conductive state (fig. 8) ([0033]: taught because (64) is made of a ferroelectric material).
In regards to claim 16, Beam teaches the limitations discussed above in addressing claim 1. Beam further teaches the limitations of a transistor assembly, comprising the HEMT according to claim 1, and further comprising a control signal generator, wherein the control signal generator is configured to apply a voltage to the gate electrode in order to set a polarization direction in a region of the third layer that is opposite the gate electrode ([0034]: e.g. V/s and gate contact (68)).
In regards to claim 17, Beam teaches the limitations discussed above in addressing claim 16. Beam further teaches the limitations wherein the control signal generator is configured to set a degree of polarization in the region of the third layer that is opposite the gate electrode by means of applying the voltage to the gate electrode in order to set a threshold voltage of the HEMT ([0034]: e.g. V/s and gate contact (68)).
In regards to claim 18, Beam teaches the limitations discussed above in addressing claim 1. Beam further teaches the limitations of a method for controlling the HEMT according to claim 1, comprising:
applying a voltage to the gate electrode in order to set a polarization direction and/or a degree of polarization of the third material, in order to set a threshold voltage of the HEMT, at which a conduction channel through the charge zone changes between an enabled state and a disabled state ([0034]: e.g. V/s and gate contact (68)).
In regards to claim 19, Beam teaches the limitations discussed above in addressing claim 18. Beam further teaches the limitations wherein setting the polarization direction and/or the degree of polarization of the third material takes place such that a threshold voltage of the HEMT, at which a conduction channel through the charge zone changes between an enabled state and a disabled state, is positive ([0034]: e.g. V/s and gate contact (68)).
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) 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Beam, in view of Soltani.
In regards to claim 20, Beam teaches a method for producing an HEMT, comprising:
providing a layer structure comprising a first layer (56), a second layer (60), and a third layer (64), which comprises a ferroelectric third material [0033] made of a third nitride compound, or comprises a ferroelectric third material made of an oxide compound, which comprises zinc, comprises a third nitride compound, or a ferroelectric third material made of an oxide compound, which comprises zinc, the third material comprising a transition metal (fig. 8) ([0033]: ScyAlzGa1-y-zN), such that
the second layer is arranged between the first layer and the third layer (fig. 8: (64) is between (68) and (60))),
a main surface of the second layer is arranged opposite a main surface of the first layer (fig. 8: e.g. bottom surface of (60) is opposite top surface of (56)) [0026], and
a charge zone (2DEG) forms along the main surface of the first layer, which provides a conduction channel in an enabled state of the HEMT (fig. 8) [0033],
applying a source contact (66) and a drain contact (70) in such a way that the charge zone is arranged electrically in series between the source contact and the drain contact (fig. 8).
Beam appears to be silent as to, but does not preclude, the limitations of a temperature treatment of the layer structure together with the source contact and the drain contact. Soltani teaches the limitations of a temperature treatment of the layer structure together with the source contact and the drain contact [0074]. It would have been obvious to one having ordinary skill in the art at the time the application at hand was filed to modify the limitations taught by Beam to include the temperature treatment step taught by Soltani to create a low ohmic contact resistance layer (Soltani [0074]).
Allowable Subject Matter
Claim(s) 11 is/are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is a statement of reasons for the indication of allowable subject matter: the closes prior art does not appear to teaches, alone or in combination, the limitations further comprising an insulation layer which is arranged between the second layer and the third layer or between the second layer and the fourth layer, wherein the insulation layer comprises an electrically conductive material.
Conclusion
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CALVIN CHOI
Patent Examiner
Art Unit 2812
/CALVIN Y CHOI/Patent Examiner, Art Unit 2812