Plasma treatment method and apparatus

• US 5,900,103 A
• Filed: 04/19/1995
• Issued: 05/04/1999
• Est. Priority Date: 04/20/1994
• Status: Expired due to Term

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Koshiishi, Akira, Tomoyasu, Masayuki
• Primary Examiner(s): DANG, THI D
• Application Number:
  US08/424,127
• Time in Patent Office: 1,476 Days
• Field of Search: 156/345, 204/298.34, 204/298.08, 118/723 E, 315/111.21
• US Class Current: 156/345.44
• CPC Class Codes: C23C 16/4405 Cleaning of reactor or parts inside the reactor by using reactive gases
• CPC Class Codes: C23C 16/4407 Cleaning of reactor or reactor parts by using wet or mechanical methods
• CPC Class Codes: C23C 16/4483 using a porous body
• CPC Class Codes: C23C 16/4485 by evaporation without using carrier gas in contact with the source material C23C16/4486 takes precedence
• CPC Class Codes: C23C 16/45565 Shower nozzles
• CPC Class Codes: C23C 16/4557 Heated nozzles
• CPC Class Codes: C23C 16/5096 Flat-bed apparatus
• CPC Class Codes: C23C 16/517 using a combination of discharges covered by two or more of groups C23C16/503 - C23C16/515
• CPC Class Codes: H01J 37/32082 Radio frequency generated discharge H01J37/32357, H01J37/32366, H01J37/32394 and H01J37/32403 take precedence
• CPC Class Codes: H01J 37/32146 Amplitude modulation, includes pulsing
• CPC Class Codes: H01J 37/32155 Frequency modulation
• CPC Class Codes: H01J 37/32165 Plural frequencies
• CPC Class Codes: H01J 37/3244 Gas supply means
• CPC Class Codes: H01J 37/32935 Monitoring and controlling tubes by information coming from the object and/or discharge
• CPC Class Codes: H01J 37/32963 End-point detection
• CPC Class Codes: Y10S 156/916 Differential etching apparatus including chamber cleaning means or shield for preventing deposits

Abstract

A plasma treatment method comprising exhausting a process chamber so as to decompress the process chamber, mounting a wafer on a suscepter, supplying a process gas to the wafer through a shower electrode, applying high frequency power, which has a first frequency f₁ lower than an inherent lower ion transit frequencies of the process gas, to the suscepter, and applying high frequency power, which has a second frequency f₂ higher than an inherent upper ion transit frequencies of the process gas, whereby a plasma is generated in the process chamber and activated species influence the wafer.

Claims

1. A plasma treatment apparatus for plasma-treating a substrate under a reduced pressure, comprising:

a chamber electrically connected to ground;

gas supply means for supplying a process gas into said chamber;

exhaust means for exhausting the chamber;

a lower electrode on which said substrate is disposed;

an upper electrode mounted within the chamber to face said lower electrode;

a first power supply connected to the lower electrode through a first matching circuit to apply a high frequency signal to the lower electrode, said high frequency signal having a first frequency f₁ lower than an inherent lower ion transit frequency of the process gas;

a second power supply to generate a high frequency signal having a second frequency f₂ higher than an inherent upper ion transit frequency of the process gas; and

an amplitude modulation circuit connected to each of said first and second power supplies for receiving high frequency signals having the first and second frequencies f₁ and f₂, the amplitude of the high frequency signal having the second frequency f₂ being modulated by the high frequency signal having the first frequency f₁, and said amplitude-modulated signal being applied to the upper electrode through the second matching circuit.

2. The plasma treatment apparatus according to claim 1, further comprising a phase controller for shifting the phase of the high frequency signal having the first frequency f₁.