# US 10,504,744 B1 · Three or more states for achieving high aspect ratio dielectric etch

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

- Number: US 10,504,744 B1
- Document ID: US10504744B1
- Status: Granted
- Kind: B1
- Application number: 16/040,502
- Filed: 2018-07-19
- Granted: 2019-12-10
- Earliest claimed: 2018-07-19
- Assignees: Lam Research Corporation
- Applicants: Lam Research Corporation
- Inventors: Takumi Yanagawa; Nikhil Dole; Ranadeep Bhowmick; Eric Hudson; Felix Leib Kozakevich; John Holland; Alexei Marakhtanov; Bradford J. Lyndaker
- Web page: https://patentgrep.com/patent/US10504744B1

## CPC

- H10P 50/73: {using masks for insulating materials}
- H01J 37/32009: {Arrangements for generation of plasma specially adapted for examination or treatment of objects, e.g. plasma sources (plasma generation in general H05H1/24)}
- H01J 37/32082: {Radio frequency generated discharge (H01J37/32357, H01J37/32366, H01J37/32394 and H01J37/32403 take precedence)}
- H01J 37/32091: {the radio frequency energy being capacitively coupled to the plasma}
- H01J 37/321: {the radio frequency energy being inductively coupled to the plasma}
- H01J 37/32174: {Circuits specially adapted for controlling the RF discharge}
- H01J 37/32183: {Matching circuits}
- H10P 50/283: {by chemical means}
- H01J 2237/334: Etching
- H10P 50/242: {of Group IV materials}
- 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

Systems and methods for applying three or more states for achieving a high aspect ratio dielectric etch operation are described. In one of the methods, a middle state is introduced between a high state and a low state. The middle state is applied to both a source radio frequency (RF) generator and a bias radio frequency (RF) generator. During the middle state, RF power is maintained to be between a high amount of RF power associated with the high state and a low amount of RF power associated with the low state to achieve the high aspect ratio dielectric etch.

## Claims

### Claim 1

A system comprising:
a plasma chamber having a first electrode and a second electrode;
an impedance matching circuit coupled to the plasma chamber;
a bias radio frequency (RF) generator coupled to the impedance matching circuit, wherein the bias RF generator is configured to supply a bias radio frequency (RF) signal to the impedance matching circuit, wherein the bias RF signal includes a first plurality of parameter levels during a repeating time period, wherein the first plurality of parameter levels include a first parameter level during a first state, a second parameter level during a second state, and a third parameter level during a third state; and
a source RF generator coupled to the impedance matching circuit, wherein the source RF generator is configured to supply a source RF signal to the impedance matching circuit, wherein the source RF signal includes a second plurality of parameter levels during the repeating time period, wherein the second plurality of parameter levels include a first parameter level during the first state, a second parameter level during the second state, and a third parameter level during the third state,
wherein the first, second and third parameter levels of the bias RF signal are different from each other,
wherein the first, second and third parameter levels of the source RF signal are different from each other.

### Claim 2 (depends on 1)

The system of claim 1, wherein the impedance matching circuit includes a bias impedance matching circuit and a source impedance matching circuit, wherein the source impedance matching circuit is configured to receive the source RF signal and provide an output to the first electrode, and wherein the bias impedance matching circuit is configured to receive the bias RF signal and provide an output to the second electrode.

### Claim 3 (depends on 2)

The system of claim 2, wherein the first electrode is an upper electrode and the second electrode is a substrate support electrode.

### Claim 4 (depends on 1)

The system of claim 1, wherein the impedance matching circuit is configured to provide an output based on the bias RF signal and the source RF signal.

### Claim 5 (depends on 4)

The system of claim 4, wherein the output from the impedance matching circuit is provided to the first electrode.

### Claim 6 (depends on 5)

The system of claim 5, wherein the first electrode is a substrate support electrode.

### Claim 7 (depends on 5)

The system of claim 5, wherein the first electrode is an upper electrode.

### Claim 8 (depends on 1)

The system of claim 1, wherein the source RF generator is configured to set the second parameter level of the source RF signal during the second state to be lower than the first parameter level of the source RF signal during the first state and higher than the third parameter level of the source RF signal during the third state, wherein the bias RF generator is configured to set the second parameter level of the bias RF signal during the second state to be lower than the first parameter level of the bias RF signal during the first state and higher than the third parameter level of the bias RF signal during the third state.

### Claim 9 (depends on 1)

The system of claim 1, wherein the source RF generator is configured to set the third parameter level of the source RF signal during the third state to be lower than the first parameter level of the source RF signal during the first state and higher than the second parameter level of the source RF signal during the second state, wherein the bias RF generator is configured to set the third parameter level of the bias RF signal during the third state to be lower than the first parameter level of the bias RF signal during the first state and higher than the second parameter level of the bias RF signal during the second state.

### Claim 10 (depends on 1)

The system of claim 1, wherein the source RF generator is configured to change a duration for which the second parameter level of the source RF signal is maintained during the second state, wherein the bias RF generator is configured to change a duration for which the second parameter level of the bias RF signal is maintained during the second state.

### Claim 11 (depends on 1)

The system of claim 1, wherein the source RF generator is configured to change the second parameter level at which the source RF signal is maintained during the second state, and wherein the bias RF generator is configured to change the second parameter level at which the bias RF signal is maintained during the second state.

### Claim 12 (depends on 1)

The system of claim 1, wherein during the first state, an etch operation is performed and during the third state, a deposition operation is performed.