Thin film forming method

Patent metadata

Field	Value
Publication number	US-12025484-B2
Application number	US-201916398126-A
Country	US
Kind code	B2
Filing date	Apr 29, 2019
Priority date	May 8, 2018
Publication date	Jul 2, 2024
Grant date	Jul 2, 2024

Abstract

A thin film forming method includes: a first operation of supplying a source gas at a first flow rate into a reactor; a second operation of purging the source gas in the reactor to an exhaust unit; a third operation of supplying a reactive gas at a second flow rate into the reactor; a fourth operation of supplying plasma into the reactor; and a fifth operation of purging the reactive gas in the reactor to the exhaust unit, wherein, during the second to fifth operations, the source gas is bypassed to the exhaust unit, and a flow rate of the source gas bypassed to the exhaust unit is less than the first flow rate. According to the thin film forming method, the consumption of the source gas and the reactive gas may be reduced, and the generation of reaction by-products in the exhaust unit may be minimized.

First claim

What is claimed is:

1. A thin film forming method comprising:
a first operation of supplying a source gas at a first flow rate via a source gas supply pipe into a reactor by a first mass flow controller;
a second operation of purging the source gas in the reactor to an exhaust unit;
a third operation of supplying a reactive gas at a second flow rate via a reactive gas supply pipe into the reactor by a second mass flow controller;
a fourth operation of supplying plasma into the reactor; and
a fifth operation of purging the reactive gas in the reactor to the exhaust unit,
wherein the first mass flow controller controls the flow rate of the source gas to transfer the source gas during the first to fifth operations,
wherein, during the second to fifth operations, the source gas is bypassed to the exhaust unit via a first gas bypass pipe by-the first mass flow controller, the first gas bypass pipe being branched off from the source gas supply pipe toward the exhaust unit before the reactor and a flow rate of the source gas bypassed to the exhaust unit is less than the first flow rate, and
wherein the first flow rate, a third flow rate, and respective processing time periods of the first to fifth operations are input to the first mass flow controller, the third flow rate being less than the first flow rate, and the first mass flow controller is programmed to adjust an amount of the source gas based on the input first flow rate, the input third flow rate, and the input respective processing time periods of the first to fifth operations, and

wherein the first mass flow controller is programmed to:
supply the source gas at the first flow rate during the first operation;
supply the source gas at the third flow rate after the first operation; and
supply the source gas at the first flow rate during a first predetermined period before the first operation, and

wherein a total processing time of the second to fifth operations is 1.5 seconds, and
the first predetermined period is 1.3 seconds or less.

2. The thin film forming method of claim 1 , wherein a path through which the bypassed source gas is discharged is the same as a path through which the purged source gas or reactive gas is discharged from the reactor.

3. The thin film forming method of claim 1 , wherein th first mass flow controller is programmed to:
supply the source gas at the first flow rate during the first operation; and
supply the source gas at the third flow rate during the second to fifth operations.

4. The thin film forming method of claim 3 , wherein a flow rate of the source gas bypassed to the exhaust unit during the second operation is gradually reduced from the first flow rate to the third flow rate, and
the flow rate of the source gas bypassed to the exhaust unit during the fifth operation is gradually increased from the third flow rate to the first flow rate.

5. The thin film forming method of claim 4 , wherein the reactive gas is bypassed to the exhaust unit by the second mass flow controller during the first, second, and fifth operations,
the second mass flow controller is programmed to:
supply the reactive gas at a second flow rate during the third and fourth operations;
supply the reactive gas at a fourth flow rate after the fourth operation, the fourth flow rate being less than the second flow rate; and
supply the reactive gas at the second flow rate during a second predetermined period before the third operation, and
the second predetermined period is started after the flow rate of the source gas bypassed to the exhaust unit during the second operation is reduced to the third flow rate.

6. The thin film forming method of claim 1 , wherein the third flow rate is greater than 0 and less than the first flow rate.

7. The thin film forming method of claim 6 , wherein the third flow rate is about ⅛ to about 1/10 of the first flow rate.

8. The thin film forming method of claim 1 , wherein the first predetermined period is shorter than the processing time of the fifth operation.

9. The thin film forming method of claim 1 , wherein a length of the first predetermined period does not affect properties of a thin film deposited in the reactor.

10. The thin film forming method of claim 9 , wherein the length of the first predetermined period does not affect a thickness and uniformity of the thin film deposited in the reactor.

11. A thin film forming method comprising:
a first operation of supplying a source gas at a first flow rate via a source gas supply pipe into a reactor by a first mass flow controller;
a second operation of purging the source gas in the reactor to an exhaust unit;
a third operation of supplying a reactive gas at a second flow rate via a reactive gas supply pipe into the reactor by a second mass flow controller;
a fourth operation of supplying plasma into the reactor; and
a fifth operation of purging the reactive gas in the reactor to the exhaust unit,
wherein the first mass flow controller controls the flow rate of the source gas to transfer the source gas during the first to fifth operations,
wherein, during the second to fifth operations, the source gas is bypassed to the exhaust unit via a first gas bypass pipe by-the first mass flow controller, the first gas bypass pipe being branched off from the source gas supply pipe toward the exhaust unit before the reactor and
a flow rate of the source gas bypassed to the exhaust unit is less than the first flow rate wherein the reactive gas is bypassed to the exhaust unit by the second mass flow controller during the first operation, the second operation, and the fifth operation,
the second flow rate, a fourth flow rate, and respective processing time periods of the first to fifth operations are input to the second mass flow controller, the fourth flow rate being less than the second flow rate, and
the second mass flow controller is programmed to, based on the input second flow rate, the input fourth flow rate, and the input respective processing time periods of the first to fifth operations:
supply the reactive gas at the second flow rate during the third and fourth operations; and
supply the reactive gas at the fourth flow rate during the first, second, and fifth operations.

12. The thin film forming method of claim 11 , wherein a path through which the bypassed source gas or reactive gas is discharged is the same as a path through which the purged source gas or reactive gas is discharged from the reactor,
as the fourth flow rate decreases, amounts of the source gas and the reaction gas reacted in the discharge path during the second operation are reduced, and
as the third flow rate decreases, the amounts of the source gas and the reactive gas reacted in the discharge path during the fifth operation are reduced.

13. The thin film forming method of claim 11 , wherein the method is performed by a substrate processing apparatus, the substrate processing apparatus comprising:
a gas supply unit;
a reactor;
the exhaust unit comprising a single exhaust line and connected to the reactor via the single exhaust line; and
an exhaust pump unit connected to the exhaust unit via the single exhaust line,
wherein the gas supply unit comprises:
the source gas supply pipe through which a source gas is supplied from the gas supply unit to the reactor;
the reactive gas supply pipe through which a reactive gas is supplied from the gas supply unit to the reactor;
the first bypass pipe branched off from the source gas supply pipe and connected to the exhaust unit; and
a second bypass pipe branched off from the reactive gas supply pipe and connected to the exhaust unit,

wherein,

Assignees

• Asm Ip Holding Bv

Inventors

• Kim Youngjae
• Kim Younghoon

Classifications

• H10P14/6336 Primary

  in the presence of a plasma [PECVD] · CPC title

• H10P14/6339

  deposition by cyclic CVD, e.g. ALD, ALE or pulsed CVD · CPC title

• H10P14/69433

  the material being a silicon nitride not containing oxygen, e.g. SixNy or SixByNz · CPC title

• H10P14/6682

  the compound being a silane, e.g. disilane, methylsilane or chlorosilane · CPC title

• G01F1/78

  Direct mass flowmeters · CPC title