# US 11,908,694 B2 · Ion beam implantation method and semiconductor device

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- Number: US 11,908,694 B2
- Document ID: US11908694B2
- Status: Granted
- Kind: B2
- Application number: 17/127,309
- Filed: 2020-12-18
- Published: 2021-06-24
- Granted: 2024-02-20
- Earliest claimed: 2019-12-20
- Assignees: Infineon Technologies AG
- Applicants: Infineon Technologies AG
- Inventors: Moriz Jelinek; Michael Hell; Caspar Leendertz; Kristijan Luka Mletschnig; Hans-Joachim Schulze
- Web page: https://patentgrep.com/patent/US11908694B2

## CPC

- H10P 30/222: {characterised by the angle between the ion beam and the crystal planes or the main crystal surface (characterised by the angle between the ion beam and the mask H10P30/221)}
- H01J 37/3171: {for ion implantation}
- H10D 12/481: {having gate structures on slanted surfaces, on vertical surfaces, or in grooves, e.g. trench gate IGBTs}
- H10D 30/0291: {of vertical DMOS [VDMOS] FETs}
- H10D 30/668: {having trench gate electrodes, e.g. UMOS transistors}
- H10D 62/105: {by having particular doping profiles, shapes or arrangements of PN junctions; by having supplementary regions, e.g. junction termination extension [JTE] (IGFETs having LDD or drain extension regions H10D30/601)}
- H10D 62/107: {Buried supplementary regions, e.g. buried guard rings (multi-RESURF H10D62/111)}
- H10D 62/393: {Body regions of DMOS transistors or IGBTs (cell layout of DMOS H10D62/127)}
- H10D 62/405: {Orientations of crystalline planes}
- H10D 62/60: Impurity distributions or concentrations
- H10D 62/8325: {Silicon carbide}
- H10P 30/20: into semiconductor materials, e.g. for doping
- H10P 30/204: {into Group IV semiconductors}
- H10P 30/2042: {into crystalline silicon carbide}
- H10P 30/21: {of electrically active species}
- H10P 30/212: {Through-implantation}
- H01J 2237/24578: Spatial variables, e.g. position, distance
- H01J 2237/31703: Dosimetry
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
- H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H)
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES

## Abstract

In an example, a substrate is oriented to a target axis, wherein a residual angular misalignment between the target axis and a preselected crystal channel direction in the substrate is within an angular tolerance interval. Dopant ions are implanted into the substrate using an ion beam that propagates along an ion beam axis. The dopant ions are implanted at implant angles between the ion beam axis and the target axis. The implant angles are within an implant angle range. A channel acceptance width is effective for the preselected crystal channel direction. The implant angle range is greater than 80% of a sum of the channel acceptance width and twofold the angular tolerance interval. The implant angle range is smaller than 500% of the sum of the channel acceptance width and twofold the angular tolerance interval.

## Claims

### Claim 1

An ion beam implantation method, comprising:
orienting a substrate to a target axis, wherein a residual angular misalignment exists between the target axis and a preselected crystal channel direction in the substrate and is within an angular tolerance interval, wherein a channel acceptance width is effective for the preselected crystal channel direction;
determining an implant angle range, for dopant ion implantation, that is greater than 80%, and smaller than 500%, of a sum of (i) the channel acceptance width and (ii) twofold the angular tolerance interval that the residual angular misalignment is within; and
implanting, at implant angles within the implant angle range and through a first substrate main surface of the substrate, dopant ions into the substrate using an ion beam propagating along an ion beam axis, wherein:
the implant angles are between the ion beam axis and the target axis; and
the ion beam impinges in a same sub-region of the first substrate main surface for the implant angles at which the dopant ions are implanted.

### Claim 2 (depends on 1)

The method according to claim 1, wherein:
the ion beam continuously sweeps the implant angle range at least once to implant the dopant ions into the substrate.

### Claim 3 (depends on 1)

The method according to claim 1, wherein:
implanting the dopant ions comprises performing nmax implant sub-processes at nmax different implant angles;
the implant angles comprise the nmax different implant angles; and
nmax is at least 2.

### Claim 4 (depends on 3)

The method according to claim 3, wherein:
the nmax different implant angles are equally spaced.

### Claim 5 (depends on 3)

The method according to claim 3, wherein:
the nmax implant sub-processes comprise one or more implant sub-process pairs; and
implant angles of an implant sub-process pair of the one or more implant sub-process pairs are symmetric with respect to the target axis.

### Claim 6 (depends on 3)

The method according to claim 3, wherein:
at least one of the nmax different implant angles deviates by at most 0.3 degrees from 0 degrees.

### Claim 7 (depends on 3)

The method according to claim 3, wherein:
neighboring implant angles of the nmax different implant angles differ from each other by at most 0.5 degrees.

### Claim 8 (depends on 1)

The method according to claim 1, wherein:
the implant angle range is at most 6 degrees.

### Claim 9 (depends on 1)

The method according to claim 1, comprising:
determining an angular deviation between a lateral target direction and a lateral major crystal direction in the substrate; and
prior to implanting the dopant ions, aligning the lateral major crystal direction to the lateral target direction based upon the angular deviation.

### Claim 10

An ion beam implantation method, comprising: orienting a substrate to a target axis, wherein a residual angular misalignment exists between the target axis and a preselected crystal channel direction in the substrate and is within an angular tolerance interval, wherein a channel acceptance width is effective for the preselected crystal channel direction; determining an implant angle range, for dopant ion implantation, that is greater than 80%, and smaller than 500%, of a sum of (i) the channel acceptance width and (ii) twofold the angular tolerance interval that the residual angular misalignment is within; aligning a lateral major crystal direction in the substrate based upon an angular deviation; and implanting, at implant angles within the implant angle range and through a first substrate main surface of the substrate, dopant ions into the substrate using an ion beam propagating along an ion beam axis, wherein: the implant angles are between the ion beam axis and the target axis; and the ion beam impinges in a same sub-region of the first substrate main surface for the implant angles at which the dopant ions are implanted.

### Claim 11 (depends on 10)

The method according to claim 10, wherein: the ion beam continuously sweeps the implant angle range at least once to implant the dopant ions into the substrate.

### Claim 12 (depends on 10)

The method according to claim 10, wherein: implanting the dopant ions comprises performing nmax implant sub-processes at nmax different implant angles; the implant angles comprise the nmax different implant angles; and nmax is at least 2.

### Claim 13 (depends on 12)

The method according to claim 12, wherein: the nmax different implant angles are equally spaced.

### Claim 14 (depends on 12)

The method according to claim 12, wherein: the nmax implant sub-processes comprise one or more implant sub-process pairs; and implant angles of an implant sub-process pair of the one or more implant sub-process pairs are symmetric with respect to the target axis.

### Claim 15 (depends on 12)

The method according to claim 12, wherein: at least one of the nmax different implant angles deviates by at most 0.3 degrees from 0 degrees.

### Claim 16

An ion beam implantation method, comprising: orienting a substrate to a target axis, wherein a residual angular misalignment exists between the target axis and a preselected crystal channel direction in the substrate and is within an angular tolerance interval, wherein a channel acceptance width is effective for the preselected crystal channel direction; determining an implant angle range, for dopant ion implantation, that is greater than 80%, and smaller than 500%, of a sum of (i) the channel acceptance width and (ii) twofold the angular tolerance interval that the residual angular misalignment is within; aligning a lateral major crystal direction in the substrate; and implanting, at implant angles within the implant angle range and through a first substrate main surface of the substrate, dopant ions into the substrate using an ion beam propagating along an ion beam axis, wherein: the implant angles are between the ion beam axis and the target axis; and the ion beam impinges in a same sub-region of the first substrate main surface for the implant angles at which the dopant ions are implanted.

### Claim 17 (depends on 16)

The method according to claim 16, wherein: the ion beam continuously sweeps the implant angle range at least once to implant the dopant ions into the substrate.

### Claim 18 (depends on 16)

The method according to claim 16, wherein: implanting the dopant ions comprises performing nmax implant sub-processes at nmax different implant angles; the implant angles comprise the nmax different implant angles; and nmax is at least 2.

### Claim 19 (depends on 18)

The method according to claim 18, wherein: the nmax different implant angles are equally spaced.

### Claim 20 (depends on 18)

The method according to claim 18, wherein: the nmax implant sub-processes comprise one or more implant sub-process pairs; and implant angles of an implant sub-process pair of the one or more implant sub-process pairs are symmetric with respect to the target axis.eam axis and the target axis; and the ion beam impinges in a same sub-region of the first substrate main surface for the implant angles at which the dopant ions are implanted.