Etching method

Patent metadata

Field	Value
Publication number	US-2016049314-A1
Application number	US-201414779670-A
Country	US
Kind code	A1
Filing date	Apr 22, 2014
Priority date	Apr 26, 2013
Publication date	Feb 18, 2016
Grant date	—

Abstract

An etching method for etching an object to be processed in a processing chamber including a first electrode and a second electrode disposed facing the first electrode and configured to receive the object to be processed thereon is provided that includes steps of intermittently supplying first high frequency power to either the first electrode or the second electrode while supplying second high frequency power lower than the first high frequency power to the second electrode, supplying a process gas containing hydrogen bromide HBr and oxygen O 2 into the processing chamber, and etching a poly silicon film deposited on the object to be processed into a mask pattern of a silicon-containing oxide film patterned by a spacer double patterning method by plasma generated from the process gas.

First claim

1 . An etching method for etching an object to be processed in a processing chamber including a first electrode and a second electrode disposed facing the first electrode and configured to receive the object to be processed thereon, comprising steps of:
intermittently supplying first high frequency power to either the first electrode or the second electrode while supplying second high frequency power lower than the first high frequency power to the second electrode; supplying a process gas containing hydrogen bromide HBr and oxygen O 2 into the processing chamber; and etching a poly silicon film deposited on the object to be processed into a mask pattern of a silicon-containing oxide film patterned by a spacer double patterning method by plasma generated from the process gas.

2 . The etching method as claimed in claim 1 , wherein the step of etching includes
a main etching step of etching the poly silicon film into the mask pattern of the silicon-containing oxide film by the plasma generated from the process gas, and an over etching step of further etching the poly silicon film into the mask pattern of the silicon-containing oxide film after the main etching step, wherein the first high frequency power is intermittently supplied in the main etching step and the over etching step.

3 . The etching method as claimed in claim 1 , wherein the step of etching includes
a main etching step of etching the poly silicon film into the mask pattern of the silicon-containing oxide film by the plasma generated from the process gas, and an over etching step of further etching the poly silicon film into the mask pattern of the silicon-containing oxide film after the main etching step, wherein the first high frequency power is continuously supplied in the main etching step, and the first high frequency power is intermittently supplied in the over etching step.

4 . The etching method as claimed in claim 2 , wherein among each of the main etching step and the over etching step, in the step of intermittently supplying the first high frequency power, the supplied process gas further contains any one of chloride Cl 2 , fluoromethane CH 3 F and fluoroform CHF 3 .

5 . The etching method as claimed in claim 1 , wherein a percentage of a flow rate of oxygen O 2 to a total flow rate of hydrogen bromide HBr and oxygen O 2 contained in the process gas is in a range of 0.3% to 5%.

Assignees

• Tokyo Electron Ltd

Inventors

• Nakahara Yoichi

Classifications

• H10P76/4085

  characterised by the processes involved to create the masks · CPC title

• H10P50/269

  pre- or post-treatments, e.g. anti-corrosion processes · CPC title

• H10P50/71

  using masks for conductive or resistive materials · CPC title

• H10P14/416

  of highly doped semiconductor materials, e.g. polysilicon layers or amorphous silicon layers · CPC title

• H10P50/268 Primary

  of silicon-containing layers · CPC title