Detailed Office 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 .
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.
Examiner’s Comment – Independent Claim 1
In this Office action, independent claim 1 rejected under 35 U.S.C. 103 as being unpatentable over Nejadmalayeri, Amir Hossein (2019/0018262; “Nejadmalayeri”) in view of Ren et al. (The Superjunction Device with Optimized Process Window of Breakdown Voltage, 2020 IEEE 15th International Conference on Solid-State & Integrated Circuit Technology (ICSICT), Kunming, China, 2020, pp. 1-3; “Ren”), and further in view of Simard et al. (2021/0271120; “Simard”).
Election/Restriction
In Claims filed 17 February 2026, applicant amended claims 12-17 to depend (directly or indirectly) upon claim 1. Applicant’s election without traverse of claims 1-17 in the reply filed on 17 February 2026 is acknowledged.
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.
Claims 1-17
Claims 1-17 are rejected under 35 U.S.C. 103 as being unpatentable over Nejadmalayeri, Amir Hossein (2019/0018262; “Nejadmalayeri”) in view of Ren et al. (The Superjunction Device with Optimized Process Window of Breakdown Voltage, 2020 IEEE 15th International Conference on Solid-State & Integrated Circuit Technology (ICSICT), Kunming, China, 2020, pp. 1-3; “Ren”), and further in view of Simard et al. (2021/0271120; “Simard”).
Regarding claim 1, Nejadmalayeri discloses in figures 16 and 17, and related figures and text, for example, Nejadmalayeri – Selected Text, embodiments of silicon-based optical modulators comprising rib-like raised waveguide section hosting p-n junctions disposed upon slab-like thin sections (shown but not labeled). Nejadmalayeri, figures 16 and 17, and related figures and text, for example, Nejadmalayeri – Selected Text.
Nejadmalayeri – Figures 16 and 17
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Nejadmalayeri – Selected Text
Abstract. We disclose herein an optical apparatus comprising an optical signal path which is driven by a plurality of electrical drivers. The electrical drivers are configured to optimise delays between two adjacent electrical drivers. The delays are optimised such that power loss in the optical apparatus is reduced.
[0249] The current invention can be generally applied to any platform, including but not limited to any combination of any of elemental semiconductors, alloy semiconductors, crystalline semiconductors, poly-crystalline semiconductors, amorphous semiconductors, binary semiconductors, ternary semiconductors, quaternary semiconductors, ferroelectric crystals, organic or inorganic materials with Pockels effect, silicon (Si), germanium (Ge), silicon germanium (SiGe), indium phosphide (InP), gallium arsenide (GaAs), lithium niobate (LiNbO.sub.3), Barium Titanate (BaTiO.sub.3), Potassium Titanyl Phosphate (KTP), electro-optic polymers, thermo-optic polymers, or graphene. Furthermore, various mechanisms may be used for modulating the properties of the optical signal, including but not limited to, carrier depletion, carrier injection, metal-oxide semiconductor (MOS) capacitance, plasma dispersion effect, Franz-Keldysh effect, Pockels effect, quantum confined Stark effect, or electro-optic Kerr effect.
[0270] FIG. 14 illustrates an exemplary optical modulating element. It is a semiconductor p-n structure where the phase or amplitude of the optical signal may be controlled by applying an electrical signal to its ports 1410, 1420. The raised portion 1440, which comprises the p-type region and the n-type region, is a waveguide portion carrying the optical signal. The structure shown in the figure may be used as the optical modulating element in FIG. 12, wherein the waveguide portion 1440 may correspond to the optical path 12000.
[0272] FIG. 16 illustrates an alternative exemplary modulating element. It may be used in variety of structures such as a meandered structure similar to FIG. 12. The n-p-p-n semiconductor structure in this example comprises two optical waveguides (the two raised p-n sections) 1640, 1650 and has two electrical ports 1610, 1620. The operation of the structure can be understood by a person familiar with the art by referring to [33]. The structure shown in the figure may be used as the optical modulating element in FIG. 12. For example, in FIG. 12, sub-section 4 of section 4, the ports 12441 and 12442 may correspond to ports 1620 and 1610 in FIG. 16, respectively; and the optical signal path 12000 may correspond to two waveguide portions of this figure.
[0273] FIG. 17 illustrates an alternative exemplary modulating element. This figure is very similar to FIG. 16, but the n-p-p-n structure comprises three electrical ports 1710, 1720 and 1760 instead of two ports of FIG. 16. The third electrical port 1760 which is placed in the middle p++ section 1770 which may be used in conjunction with an inductive element for at least one of DC bias of the semiconductor structure for prevention of charge build-up. The high frequency operation of the structure is however similar to FIG. 16 since at high frequency the inductive element is effectively open-circuit. The semiconductor structure in this example comprises two optical waveguide portions (the two raised p-n sections) 1740, 1760. Each of these two waveguides may correspond to a separate arm of a Mach-Zehnder interferometer based optical modulator.
[0274] The structure shown in the figure may be used as the optical modulating element in FIG. 12. For example, in FIG. 12, sub-section 4 of section 4, the ports 12441 and 12442 may correspond to ports 1720 and 1710 in FIG. 16, respectively; and the optical signal path 12000 may correspond to two waveguide portions of this figure. It is understood by those skilled in the art, that if FIG. 17 is used as the optical modulating element, an extra middle port needs to be incorporated into the structure of FIG. 12 to which the middle pad 1750 of FIG. 17 will correspond.
Claim 1. An apparatus comprising: a plurality of electrical drivers; at least one optical signal path comprising a plurality of sections, wherein at least one section comprises a plurality of sub-sections, wherein at least some of the plurality of sub-sections each comprises an optical modulating element, wherein at least some of the optical modulating elements each is coupled with at least one of said plurality of electrical drivers; wherein said each coupled electrical driver is configured to generate at least one electrical signal for modulating at least one of the propagation properties of an optical signal through said at least one optical signal path; and wherein the electrical drivers are configured such that the time delay difference between the electrical signals generated by at least two electrical drivers coupled with the optical modulating elements of respective sub-sections within said at least one section of said at least one optical signal path is smaller than or equal to seventy percent of the time-of-flight of an optical signal through said at least one section of said at least one optical signal path.
Claim 21. An apparatus according to claim 1, wherein the optical modulating element comprises a semiconductor material; and optionally wherein the semiconductor material comprises at least one of the following materials: silicon, germanium, silicon germanium, gallium arsenide, indium phosphide, and gallium nitride; or wherein the optical modulating element comprises a ferroelectric crystal material; and optionally wherein the ferroelectric crystal material comprises at least one of the following materials: Lithium Niobate, Barium Titanate, and Potassium Titanyl Phosphate; or wherein the optical modulating element comprises a material comprising electro-optic polymer.
Further regarding claim 1, Ren discloses in figures 1-11, and related text, for example, Ren – Selected Text, embodiments of junctions formed by P-pillars and N-pillars characterized by variable doping gradients which facilitate controlling e-field positions, e-field uniformity, and breakdown voltages. Ren, figures 1-11, and related text, for example, Ren – Selected Text.
Ren – Selected Text
Abstract.
In order to improve the process window of breakdown voltage (BV), a vertical variable doping(VVD) superjunction MOSFET (SJ-MOS) is proposed. The charge superposition principle is used to analyze the change of electric field(e-field) caused by the gradient doping of pillars. Compared with the uniform doping SJ-MOS, it is shown that the negative doping gradient in P-pillar and the positive doping gradient in N-pillar can make the distribution of e-field more uniform, which is beneficial to the expansion of the BV process window.
1. Introduction
Recently, SJ-MOS has become one of the most popular power semiconductor devices because of breaking the "Silicon Limit" of traditional silicon-based power devices…The charge compensation of P-pillar and N-pillar allows SJ-MOS to maintain high breakdown voltage with high doping concentration, i.e. low on-resistance. However, SJ-MOS must strictly satisfy the charge balance condition to obtain high BV. Therefore, in the actual manufacturing, the BV of SJ-MOS may fluctuate greatly because of the process errors. The effect of charge imbalance between P and N pillars on BV of the uniformly doped SJ-MOS(UD-SJ)has been investigated …however, there are few studies focus on how to improve the process window of BV(BV-Window)of SJ-MOS.
In this paper, the vertical variable doping SJ-MOS(VVD-SJ) is proposed, and the relationship of its BV and charge imbalance is studied. The charge superposition principle is used to explain the changes of e-field caused by the vertical gradient doping of the pillars. The influence of e-field distribution on the BV-Window is analyzed.
3. Discussion
3.1 Charge superposition principle The principle of charge superposition is used to analyze the changes of e-field distribution and BV-Window. The VVD-SJ can be divided into an Overlapping Balanced SJ(OB-SJ) and a PIN Diode according to the charge superposition principle… as shown in fig.3.
3.2 Discussion
1)gradient doping in the P-pillar
the e-field at point A will increase and that at point B' will decrease; for the diode component, the e-field will increase in the middle area and reduce at both ends.
3) gradient doping in both P pillar and N pillar
… it has the most uniform e-field distribution after superposition of an OB-SJ and a PIN diode.
4. Summary
Comparative research was carried out on the e-field distributions and BV-window of UD-SJ and VVD-SJ. The analysis and simulations show that the VDD-SJ with negative gradient doping in the P-pillar or positive gradient doping in the N-pillar has more uniform e-field distribution and better BV-window, which provide meaningful reference to the design and fabrication of SJ-MOS.
Consequently, in light of Ren’s disclosure of PN junctions with gradient temperatures, it would have been obvious to one of ordinary skill in the art to modify Nejadmalayeri’s silicon photonic optical modulator embodiments to disclose: an optical input; and an optical waveguide that is connected to the optical input and that is configured to propagate quasi-transverse-magnetic (quasi-TM) polarized light, wherein the optical waveguide is configured as a rib waveguide that comprises a rib arranged on a slab, wherein the rib comprises at least one dopant, wherein an average concentration of the at least one dopant in a vertical doping profile in a lowermost portion of the rib is larger than an average concentration of the at least one dopant in the vertical doping profile in an uppermost portion of the rib, wherein the uppermost portion of the rib has a height that is between 20% and 80% of a height of the rib waveguide, and wherein the lowermost portion of the rib comprises a remainder of the rib below the uppermost portion; Nejadmalayeri, figures 16 and 17, and related figures and text, for example, Nejadmalayeri – Selected Text; Ren, figures 1-11, and related text, for example, Ren – Selected Text; because the resulting configuration would facilitate designing, fabricating, and deploying optical modulator rib waveguides dimensions to support guiding Transverse Magnetic modes. Simard, figure 4, and related figures and text, for example, Simard – Selected Text.
Simard – Figure 4
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Simard – Selected Text
Abstract. An optical modulator includes a rib; and a slab interconnected to both sides of the rib; wherein the rib is dimensioned relative to the slab to support guiding of a Transverse Magnetic (TM) mode with a main lobe that propagates orthogonal to the slab and with the main lobe substantially excluded from the slab. The rib guides wavelengths in an infrared range in the TM mode. A height of the rib, relative to the slab, is about half of a width of the rib, between the slab.
[0039] In FIG. 4, the modulator 30 has similar main lobes 40 as the modulator 10 except that the TM mode is rotated by 90 degrees. That is, the main lobes of the modulator 30 are perpendicular to a slab 50. Wings 52 of the modulator 30 are similar to the wings 52 of the modulator 10, again except rotated by 90 degrees.
[0040] For the modulator 10, it is very confined vertically but not so confined horizontally. The situation is reversed for the TM mode in the modulator 30. An imaginary line 54 shows the direction where the mode is less confined. Of course, the presence of the slab 50 modifies the mode profile a bit, but the idea was to change the relative position of the slab 50 compared to the lines 54. In the modulator 10, the line 54 is colinear with the slab 50 which makes the mode confinement inside the slab 50 not as good compared to the TM mode in the modulator 30 one where the line 54 is orthogonal to the slab 50. Thus, the optical mode in the modulator 30 does not naturally penetrate in the slab 50, unlike in the modulator 10.
[0041] This has a few significant benefits:
[0042] 1) The optical mode is laterally more confined in Region I, which will improve the modulator Vπ in the modulator 30 compared to the modulator 10.
[0043] 2) Since Region I has a width similar to the waveguide width, Region II becomes very narrow in the modulator 30. The fraction of optical power located in this section being smaller, the optical losses will be smaller as well in the modulator 30 compared to the modulator 10.
[0044] Because of the boundary conditions of the electromagnetic fields, the mode does not enter significantly into Region III in the modulator 30. As a result, larger charge concentrations can be brought closer to the optical waveguide hence reducing the access resistance without increasing the propagation losses. This will improve the modulator BW.
Regarding dependent claims 2-17, it would have been obvious to one of ordinary skill in the art to modify Nejadmalayeri in view of Ren and further in view of Simard’s silicon photonic optical modulator embodiments, as applied in the rejection of claim 1, to disclose:
2. The silicon-photonic optical modulator of claim 1, wherein the average concentration of the at least one dopant in the lowermost portion is at least 1.5 times the average concentration of the at least one dopant in the uppermost portion. Nejadmalayeri, figures 16 and 17, and related figures and text, for example, Nejadmalayeri – Selected Text; Ren, figures 1-11, and related text, for example, Ren – Selected Text; Simard, figure 4, and related figures and text, for example, Simard – Selected Text.
3. The silicon-photonic optical modulator of claim 2, wherein the average concentration of the at least one dopant in the lowermost portion is at least two times the average concentration of the at least one dopant in the uppermost portion. Nejadmalayeri, figures 16 and 17, and related figures and text, for example, Nejadmalayeri – Selected Text; Ren, figures 1-11, and related text, for example, Ren – Selected Text; Simard, figure 4, and related figures and text, for example, Simard – Selected Text.
4. The silicon-photonic optical modulator of claim 1, wherein the height of the uppermost portion is between 35% and 65% of the height of the rib waveguide. Nejadmalayeri, figures 16 and 17, and related figures and text, for example, Nejadmalayeri – Selected Text; Ren, figures 1-11, and related text, for example, Ren – Selected Text; Simard, figure 4, and related figures and text, for example, Simard – Selected Text.
5. The silicon-photonic optical modulator of claim 1, wherein: the average concentration of the at least one dopant in the lowermost portion is between 1017cm-3 and 1018 cm-3, and the average concentration of the at least one dopant in the uppermost portion is less than 5x1016 cm-3. Nejadmalayeri, figures 16 and 17, and related figures and text, for example, Nejadmalayeri – Selected Text; Ren, figures 1-11, and related text, for example, Ren – Selected Text; Simard, figure 4, and related figures and text, for example, Simard – Selected Text.
6. The silicon-photonic optical modulator of claim 1, wherein the at least one dopant comprises a first dopant in a first lateral portion of the rib and a second dopant in a second lateral portion of the rib, the second lateral portion opposite the first lateral portion, wherein the first lateral portion and the second lateral portion form a semiconductor junction diode. Nejadmalayeri, figures 16 and 17, and related figures and text, for example, Nejadmalayeri – Selected Text; Ren, figures 1-11, and related text, for example, Ren – Selected Text; Simard, figure 4, and related figures and text, for example, Simard – Selected Text.
7. The silicon-photonic optical modulator of claim 6, wherein a concentration of the first dopant in a first vertical doping profile in the first lateral portion of the rib is higher in the lower portion of the rib than in the upper portion of the rib, and wherein a concentration of the second dopant in a second vertical doping profile in the second lateral portion of the rib is higher in the lower portion of the rib than in the upper portion of the rib. Nejadmalayeri, figures 16 and 17, and related figures and text, for example, Nejadmalayeri – Selected Text; Ren, figures 1-11, and related text, for example, Ren – Selected Text; Simard, figure 4, and related figures and text, for example, Simard – Selected Text.
8. The silicon-photonic optical modulator of claim 6, comprising an electrode configured to apply an electric field to the semiconductor junction diode. Nejadmalayeri, figures 16 and 17, and related figures and text, for example, Nejadmalayeri – Selected Text; Ren, figures 1-11, and related text, for example, Ren – Selected Text; Simard, figure 4, and related figures and text, for example, Simard – Selected Text.
9. The silicon-photonic optical modulator of claim 8, comprising a semiconductor contact region to which the electrode makes contact, wherein a height of the semiconductor contact region is greater than a height of the slab. Nejadmalayeri, figures 16 and 17, and related figures and text, for example, Nejadmalayeri – Selected Text; Ren, figures 1-11, and related text, for example, Ren – Selected Text; Simard, figure 4, and related figures and text, for example, Simard – Selected Text.
10. The silicon-photonic optical modulator of claim 1, wherein an effective refractive index of a TM polarization two-dimensional (2D) guided mode in the rib waveguide is greater than all effective refractive indexes of transverse-electric (TE) polarization one- dimensional (lD) guided modes in the slab. Nejadmalayeri, figures 16 and 17, and related figures and text, for example, Nejadmalayeri – Selected Text; Ren, figures 1-11, and related text, for example, Ren – Selected Text; Simard, figure 4, and related figures and text, for example, Simard – Selected Text.
11. The silicon-photonic optical modulator of claim 1, wherein the optical waveguide is a first optical waveguide, wherein the silicon-photonic optical modulator comprises a Mach-Zehnder interferometer comprising the first optical waveguide and a second optical waveguide, wherein the first optical waveguide comprises a first semiconductor junction diode based on the at least one dopant, and wherein the second optical waveguide comprises a second semiconductor junction diode based on the at least one dopant. Nejadmalayeri, figures 16 and 17, and related figures and text, for example, Nejadmalayeri – Selected Text; Ren, figures 1-11, and related text, for example, Ren – Selected Text; Simard, figure 4, and related figures and text, for example, Simard – Selected Text.
12. The silicon-photonic optical modulator of claim 1, wherein a width of the rib is in a range from 250 nm to 400 nm. Nejadmalayeri, figures 16 and 17, and related figures and text, for example, Nejadmalayeri – Selected Text; Ren, figures 1-11, and related text, for example, Ren – Selected Text; Simard, figure 4, and related figures and text, for example, Simard – Selected Text.
13. The silicon-photonic optical modulator of claim 12, wherein a height of the rib is greater than the width of the rib. Nejadmalayeri, figures 16 and 17, and related figures and text, for example, Nejadmalayeri – Selected Text; Ren, figures 1-11, and related text, for example, Ren – Selected Text; Simard, figure 4, and related figures and text, for example, Simard – Selected Text.
14. The silicon-photonic optical modulator of claim 12, wherein a height of the rib is in a range of 300 nm to 400 nm, and wherein a thickness of the slab is in a range of 50 nm to 150 nm.
15. The silicon-photonic optical modulator of claim 12, wherein the width of the rib is in a range from 250 nm to 360 nm. Nejadmalayeri, figures 16 and 17, and related figures and text, for example, Nejadmalayeri – Selected Text; Ren, figures 1-11, and related text, for example, Ren – Selected Text; Simard, figure 4, and related figures and text, for example, Simard – Selected Text.
16. The silicon-photonic optical modulator of claim 12, wherein the optical waveguide is a first rib waveguide, and wherein the silicon-photonic optical modulator comprises a second rib waveguide, and wherein a gap between the first rib waveguide and the second rib waveguide is less than 500 nm wide. Nejadmalayeri, figures 16 and 17, and related figures and text, for example, Nejadmalayeri – Selected Text; Ren, figures 1-11, and related text, for example, Ren – Selected Text; Simard, figure 4, and related figures and text, for example, Simard – Selected Text.
17. The silicon-photonic optical modulator of claim 16, wherein a height of the first rib waveguide is greater than a height of the second rib waveguide by at least 10 nm in at least part of the silicon-photonic optical modulator. Nejadmalayeri, figures 16 and 17, and related figures and text, for example, Nejadmalayeri – Selected Text; Ren, figures 1-11, and related text, for example, Ren – Selected Text; Simard, figure 4, and related figures and text, for example, Simard – Selected Text.
because the resulting configurations would facilitate designing, fabricating, and deploying optical modulator rib waveguides dimensions to support guiding Transverse Magnetic modes. Simard, figure 4, and related figures and text, for example, Simard – Selected Text.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to PETER RADKOWSKI whose telephone number is (571)270-1613. The examiner can normally be reached on M-Th 9-5. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Thomas Hollweg, can be reached on (571) 270-1739. The fax phone number for the organization where this application or proceeding is assigned is (571) 273-8300.
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/PETER RADKOWSKI/Primary Examiner, Art Unit 2874
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