# US 2022/0285482 A1 · Trench capacitor device for superconducting electronic circuit and superconducting qubit device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2022/0285482 A1 - Document ID: US20220285482A1 - Status: Published application - Kind: A1 - Application number: 17/682,587 - Filed: 2022-02-28 - Published: 2022-09-08 - Earliest claimed: 2021-03-02 - Assignees: Imec Vzw - Applicants: Imec Vzw - Inventors: Anton Potocnik - Web page: https://patentgrep.com/patent/US20220285482A1 ## CPC - H01G 4/005: Electrodes - H10D 1/042: {using deposition processes to form electrode extensions} - G06N 10/00: Quantum computing, i.e. information processing based on quantum-mechanical phenomena - H10D 1/716: {having vertical extensions} - H10N 60/01: Manufacture or treatment - H10N 60/805: {for Josephson-effect devices} - H10N 69/00: Integrated devices, or assemblies of multiple devices, comprising at least one superconducting element covered by group H10N60/00 - H03K 19/195: using superconductive devices - H10D 64/608: {being superconducting} - H10N 60/12: Josephson-effect devices - H10W 20/4484: {Superconducting materials} - H10W 70/668: {Superconducting materials} - H01G: CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE (selection of specified materials as dielectric H01B3/00; capacitors having potential barriers H10D1/62, H10K10/10) - H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES - G06N: COMPUTING ARRANGEMENTS BASED ON SPECIFIC COMPUTATIONAL MODELS - H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR - H03K: PULSE TECHNIQUE (measuring pulse characteristics G01R; modulating sinusoidal oscillations with pulses H03C; transmission of digital information H04L; discriminator circuits detecting phase difference between two signals by counting or integrating cycles of oscillation H03D3/04; automatic control, starting, synchronisation or stabilisation of generators of electronic oscillations or pulses where the type of generator is irrelevant or unspecified H03L; coding, decoding or code conversion, in general H03M) - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 ## Abstract The disclosure relates to a trench capacitor device for a superconducting electronic circuit. The trench capacitor device includes a substrate, a first capacitor electrode, and a second capacitor electrode, each electrode including a superconductor and extending into the substrate. The first electrode is circumferentially enclosed by the second electrode such that an inwardly facing surface of the second electrode faces an outwardly facing surface of the first electrode. ## Claims ### Claim 1 A trench capacitor device comprising: a substrate; a first electrode comprising a superconductor and extending into the substrate; and a second electrode comprising a superconductor and extending into the substrate, the first electrode being circumferentially enclosed by the second electrode such that an inwardly facing surface of the second electrode faces an outwardly facing surface of the first electrode. ### Claim 2 (depends on 1) The trench capacitor device according to claim 1, wherein the inwardly facing surface and the outwardly facing surface are separated by a dielectric material of the substrate. ### Claim 3 (depends on 1) The trench capacitor device according to claim 1, wherein the first electrode and the second electrode are separated by crystalline silicon. ### Claim 4 (depends on 1) The trench capacitor device according to claim 1, wherein the inwardly facing surface and the outwardly facing surface are separated by an air gap. ### Claim 5 (depends on 1) The trench capacitor device according to claim 1, wherein the inwardly facing surface and the outwardly facing surface are separated by a vacuum. ### Claim 6 (depends on 1) The trench capacitor device according to claim 1, wherein the first electrode has a rounded cross-sectional shape. ### Claim 7 (depends on 1) The trench capacitor device according to claim 1, wherein the second electrode has a rounded tubular cross-sectional shape. ### Claim 8 (depends on 1) The trench capacitor device according to claim 1, wherein the first electrode and the second electrode are coaxially arranged. ### Claim 9 (depends on 1) The trench capacitor device according to claim 1, wherein the first electrode has a decreasing radial dimension along a first direction from a first side of the substrate towards a second side of the substrate. ### Claim 10 (depends on 9) The trench capacitor device according to claim 9, wherein the second electrode has a decreasing wall thickness along a second direction from the second side towards the first side. ### Claim 11 (depends on 1) The trench capacitor device according to claim 1, wherein the first electrode is arranged in a first trench extending into the substrate from a first side towards a second side of the substrate. ### Claim 12 (depends on 11) The trench capacitor device according to claim 11, wherein the second electrode is arranged in a second trench extending into the substrate from the second side towards the first side. ### Claim 13 (depends on 1) The trench capacitor device according to claim 1, further comprising: a first ground plane arranged on a first side of the substrate; a second ground plane arranged on a second side of the substrate opposite the first side; a first Josephson junction connected between the first electrode and the second electrode and arranged on the first ground plane; a third electrode comprising a superconductor, wherein the third electrode is in contact with the first ground plane and extends into the substrate; a fourth electrode comprising a superconductor, wherein the fourth electrode is in contact with the second ground plane and extends into the substrate, the third electrode being circumferentially enclosed b the fourth electrode such that an inwardly facing surface of the fourth electrode faces an outwardly facing surface of the third electrode; and a second Josephson junction connected between the third electrode and the fourth electrode and arranged on the first ground plane. ### Claim 14 A superconducting qubit device comprising: a trench capacitor device comprising: a substrate; a first electrode comprising a superconductor and extending into the substrate; and a second electrode comprising a superconductor and extending into the substrate, the first electrode being circumferentially enclosed by the second electrode such that an inwardly facing surface of the second electrode faces an outwardly facing surface of the first electrode; and a Josephson junction connected between the first electrode and the second electrode of the trench capacitor device. ### Claim 15 (depends on 14) The superconducting qubit device according to claim 14, further comprising a first ground plane arranged on a first side of the substrate and a second ground plane arranged on a second side, wherein a lower electrode layer of the Josephson junction abuts the first ground plane, the second electrode abuts the second ground plane, and the first electrode is connected to an upper electrode layer of the Josephson junction. ### Claim 16 (depends on 15) The superconducting qubit device according to claim 15, wherein a portion of the second electrode extends completely through the substrate to abut the first ground plane. ### Claim 17 (depends on 15) The superconducting qubit device according to claim 15, further comprising a superconductor via arranged to extend through the substrate to interconnect the first ground plane and the second ground plane. ### Claim 18 (depends on 15) The superconducting qubit device according to claim 15, further comprising a feed line arranged on the first side and capacitively coupled to the trench capacitor device. ### Claim 19 A method comprising: forming in a substrate of crystalline silicon a first trench and a second trench, such that first trench is circumferentially enclosed by the second trench; and depositing a superconductor to form a first electrode in the first trench and a second electrode in the second trench, the first electrode being circumferentially enclosed by the second electrode such that an inwardly facing surface of the second electrode faces an outwardly facing surface of the first electrode. ### Claim 20 (depends on 19) The method according to claim 19, wherein forming the first trench comprises etching from a first side of the substrate and forming the second trench comprises etching from a second side of the substrate opposite the first side.