# US 2014/0151853 A1 · Ion Implantation Apparatus, Ion Implantation Method, and Semiconductor Device

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2014/0151853 A1
- Document ID: US20140151853A1
- Status: Published application
- Kind: A1
- Application number: 14/172,091
- Filed: 2014-02-04
- Published: 2014-06-05
- Earliest claimed: 2008-12-16
- Assignees: National University Corporation Tohoku University
- Applicants: National University Corporation Tohoku University
- Inventors: Tadahiro OHMI; Tetsuya GOTO
- Web page: https://patentgrep.com/patent/US20140151853A1

## CPC

- H10P 72/0471: {comprising at least one ion or electron beam chamber}
- H01J 37/32412: {Plasma immersion ion implantation}
- H10P 30/204: {into Group IV semiconductors}
- H10P 30/208: {of electrically inactive species}
- H10P 32/1204: {from a plasma phase}
- 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)

## Abstract

In the plasma-based ion implantation for accelerating positive ions of a plasma and implanting the positive ions into a substrate to be processed on a holding stage in a processing chamber where the plasma has been excited, ion implantation is achieved in the following manner: an RF power having a frequency of 4 MHz or greater is applied to the holding stage to cause a self-bias voltage to generate on the surface of the substrate. The RF power is applied a plurality of times in the form of pulses.

## Claims

### Claim 1

An ion implantation apparatus, comprising:
a processing chamber which is evacuated and in which a plasma is excited and,
a holding stage provided in the processing chamber and holding a substrate to be processed,
wherein an RF power is applied to the holding stage to generate a self-bias voltage on a surface of the substrate so that positive ions in the plasma are accelerated and implanted into the substrate,
wherein the RF power has a frequency of 4 MHz or more and is applied in the form of pulses so that ion implantation is dividedly carried out a plurality of times.

### Claim 2 (depends on 1)

The ion implantation apparatus according to claim 1, wherein the plasma is excited by causing an electromagnetic wave having a frequency selected from a range of 100 MHz to 3 GHz to propagate as a metal surface wave into the processing chamber and
introducing a gas for plasma excitation into the processing chamber.

### Claim 3 (depends on 1)

The ion implantation apparatus according to claim 1, wherein the holding stage has an electrostatic chuck function,
a gas is filled into a space between the holding stage and the substrate by the electrostatic chuck function,
a filling pressure of the gas is set higher than a pressure in the processing chamber, and
a shield plate is provided around the holding stage for preventing the gas leaking from the space from entering a plasma exciting region.

### Claim 4 (depends on 1)

An ion implantation method that carries out ion implantation using the ion implantation apparatus according to claim 1.

### Claim 5 (depends on 4)

The ion implantation method according to claim 4, wherein the ion implantation is carried out using at least a plurality of self-bias voltages by changing the RF power to be applied to the holding stage.

### Claim 6 (depends on 5)

The ion implantation method according to claim 5, wherein the surface of the substrate comprises a semiconductor crystal containing silicon, the method comprising:
a step of carrying out the ion implantation while amorphizing the semiconductor crystal by at least a first self-bias voltage, and
a step of causing an ion implantation density of an outermost surface of the semiconductor crystal to be at least 1×1020 cm−3 or more by a second self-bias voltage.

### Claim 7 (depends on 4)

The ion implantation method according to claim 4, wherein the gas for plasma excitation is a gas of a fluoride of an implantation atom.

### Claim 8 (depends on 4)

The ion implantation method according to claim 4, wherein the gas for plasma excitation is at least one gas selected from the group comprising BF3, PF3, and AsF3.

### Claim at position 9

-10. (canceled)

### Claim 11 (depends on 1)

A semiconductor device manufactured using the ion implantation apparatus according to claim 1.

### Claim 12 (depends on 6)

A semiconductor device manufactured using the ion implantation method according to claim 6.

### Claim 13 (depends on 4)

A semiconductor device manufacturing method, comprising:
a step of carrying out ion implantation by the ion implantation method according to claim 4.

### Claim 14 (depends on 1)

The ion implantation apparatus according to claim 1, wherein a pulse width of the RF power is shorter than a pulse stop period of the RF power.

### Claim 15 (depends on 7)

A semiconductor device manufactured using the ion implantation method according to claim 7.