# US 2022/0037545 A1 · Fin-based photodetector structure > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2022/0037545 A1 - Document ID: US20220037545A1 - Status: Published application - Kind: A1 - Application number: 17/504,614 - Filed: 2021-10-19 - Published: 2022-02-03 - Earliest claimed: 2020-01-13 - Assignees: GlobalFoundries U.S. Inc. - Applicants: GlobalFoundries U.S. Inc. - Inventors: Ajey Poovannummoottil Jacob; Yusheng Bian; Steven Shank - Web page: https://patentgrep.com/patent/US20220037545A1 ## CPC - H10F 77/147: {Shapes of bodies} - H10F 30/221: the potential barrier being a PN homojunction - H10F 30/223: the potential barrier being a PIN barrier - H10F 71/121: {The active layers comprising only Group IV materials} - H10F 71/1212: {consisting of germanium} - H10F 71/131: {Recrystallisation; Crystallization of amorphous or microcrystalline semiconductors} - H10F 77/122: comprising only Group IV materials - H10F 77/413: {directly associated or integrated with the devices, e.g. back reflectors (directly associated or integrated with photovoltaic cells H10F77/42)} - Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product - H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract A photodetector disclosed herein includes an N-doped waveguide structure defined in a semiconductor material, wherein the N-doped waveguide structure comprises a plurality of first fins. Each adjacent pair of the plurality of first fins is separated by a trench formed in the semiconductor material. The photodetector also includes a detector structure positioned on the N-doped waveguide structure, wherein a portion of the detector structure is positioned laterally between the plurality of first fins. The detector structure comprises a single crystal semiconductor material. The photodetector also includes a first diffusion region that extends from the bottom surface of the trench into the semiconductor material, wherein the first diffusion region comprises atoms of the single crystal semiconductor material of the detector structure. ## Claims ### Claim 1 A photodetector, comprising: a waveguide structure defined in a semiconductor material, the waveguide structure comprising a plurality of first fins, wherein each adjacent pair of the plurality of first fins is separated by a trench; a detector structure positioned on the waveguide structure, wherein a portion of the detector structure is positioned laterally between the plurality of first fins, wherein the detector structure comprises a single crystal semiconductor material; a diffusion region that extends from a bottom surface of the trench into the semiconductor material, wherein the diffusion region comprises atoms of the single crystal semiconductor material of the detector structure; at least one contact region positioned in the semiconductor material; and a contact region positioned in the detector structure. ### Claim 2 (depends on 1) The photodetector of claim 1, wherein the diffusion region further comprises atoms of the semiconductor material. ### Claim 3 (depends on 1) The photodetector of claim 1, wherein the waveguide structure has a dopant concentration of an N-type dopant that falls within a range of 1E18-1E20 ions/cm3 and the detector structure is doped with a P-type dopant and has a dopant concentration of a P-type dopant that falls within a range of 1E18-1E20 ions/cm3. ### Claim 4 (depends on 1) The photodetector of claim 1, wherein at least a portion of a vertical thickness of the detector structure is substantially free of a dopant material. ### Claim 5 (depends on 1) The photodetector of claim 1, further comprising a sidewall spacer positioned on each of the plurality of first fins, wherein the portion of the detector structure is laterally separated from the plurality of first fins by at least the sidewall spacer positioned on each of the plurality of fins. ### Claim 6 (depends on 1) The photodetector of claim 1, wherein the detector structure is a unitary structure comprising a body and a plurality of second fins extending from the body, wherein the second fins are interleaved with the first fins. ### Claim 7 (depends on 1) The photodetector of claim 1, wherein the detector structure comprises a plurality of individual elements, wherein at least one of the plurality of individual elements is positioned laterally between the plurality of first fins. ### Claim 8 (depends on 1) The photodetector of claim 1, wherein the detector structure comprises one of a germanium-containing material, a substantially pure germanium, or a silicon-germanium material, and wherein the waveguide structure comprises one of the germanium-containing material, the substantially pure germanium, or the silicon-germanium material ### Claim 9 (depends on 1) The photodetector of claim 1, further comprising a second diffusion region that extends from the bottom surface of the trench into the portion of the detector structure that is positioned laterally between the plurality of first fins, wherein the second diffusion region comprises atoms of the semiconductor material. ### Claim 10 (depends on 9) The photodetector of claim 9, wherein the second diffusion region further comprises atoms of the single crystal semiconductor material of the detector structure. ### Claim 11 A photodetector, comprising: a waveguide structure defined in a semiconductor material, the waveguide structure comprising a plurality of first fins, wherein each adjacent pair of the plurality of first fins is separated by a trench formed in the semiconductor material, the trench comprising a bottom surface; a detector structure positioned on the waveguide structure, wherein a portion of the detector structure is positioned laterally between the plurality of first fins, wherein the detector structure comprises single crystal germanium; a diffusion region that extends from the bottom surface of the trench into the semiconductor material, wherein the diffusion region comprises germanium atoms and silicon atoms; at least one contact region positioned in the semiconductor material; and a contact region positioned in the detector structure. ### Claim 12 (depends on 11) The photodetector of claim 11, wherein the semiconductor material is an active semiconductor layer of a semiconductor-on-insulator (SOI) structure and wherein the semiconductor material comprises one of a silicon-containing material, a substantially pure silicon material, or a silicon germanium material. ### Claim 13 (depends on 11) The photodetector of claim 11, wherein at least a portion of a vertical thickness of the detector structure is substantially free of a dopant material. ### Claim 14 (depends on 11) The photodetector of claim 11, further comprising a sidewall spacer positioned on each of the plurality of first fins, wherein the portion of the detector structure is laterally separated from the plurality of first fins by at least the sidewall spacer positioned on each of the plurality of first fins. ### Claim 15 (depends on 11) The photodetector of claim 11, wherein the detector structure is a unitary structure comprising a body and a plurality of second fins extending from the body, wherein the second fins are interleaved with the first fins. ### Claim 16 (depends on 11) The photodetector of claim 11, wherein the detector structure comprises a plurality of individual elements, wherein at least one of the plurality of individual elements is positioned laterally between the plurality of first fins. ### Claim 17 (depends on 11) The photodetector of claim 11, further comprising a second diffusion region that extends from the bottom surface of the trench into the portion of the detector structure that is positioned laterally between the plurality of first fins, wherein the second diffusion region comprises germanium atoms and silicon atoms. ### Claim 18 A method, comprising: forming a plurality of first fins in a semiconductor material to define a waveguide structure; depositing a layer of an amorphous semiconductor material on the waveguide structure, wherein portions of the layer of amorphous semiconductor material are positioned laterally between the plurality of first fins; patterning the layer of amorphous semiconductor material to form a detector structure; forming a layer of insulating material above the detector structure; with the layer of insulating material in position, performing a thermal melt growth process to convert substantially all of the layer of amorphous semiconductor material into a layer of single crystal semiconductor material; forming at least one contact region in the semiconductor material; and forming a contact region in the detector structure. ### Claim 19 (depends on 18) The method of claim 18, wherein the layer of amorphous semiconductor material comprises amorphous germanium, and wherein the layer of single crystal semiconductor material comprises single crystal germanium. ### Claim 20 (depends on 18) The method of claim 18, wherein performing the thermal melt growth process comprises performing the thermal melt growth process to form a first diffusion region that extends from the bottom surface of the trench into the semiconductor material, wherein the first diffusion region comprise atoms of the single crystal semiconductor material of the detector structure.