Dry etching endpoint detection system

• US 6,207,008 B1
• Filed: 12/14/1998
• Issued: 03/27/2001
• Est. Priority Date: 12/15/1997
• Status: Expired due to Fees

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Kijima, Masato
• Primary Examiner(s): Mills, Gregory
• Assistant Examiner(s): HASSANZADEH, PARVIZ
• Application Number:
  US09/210,925
• Time in Patent Office: 834 Days
• Field of Search: 216/60, 216/67, 216/59, 156/345, 156/626.1, 156/627.1, 356/72, 438/714
• US Class Current: 156/345.13
• CPC Class Codes: G01N 21/68 using high frequency electric fields
• 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

Abstract

A method and system for determining a dry etching endpoint, at which a dry etching process should be terminated. The dry etching process is carried out in a plasma etching system and comprises the steps of detecting an intensity of light emission generated in the dry etching process, the light emission being extracted through a window located on a side wall portion of a reaction chamber below a horizontal plane which is defined by a surface of a body to be etch treated. The detected intensity is compared to a predetermined threshold level.

Claims

1. A method of determining a dry etching endpoint, at which a dry etching process should be terminated, said dry etching process being carried out in a plasma etching system including an etching chamber, said method comprising:

detecting an intensity of light emission occurring in the etching chamber during a dry etching process, said light emission detection being performed through a window located on a side wall portion of a reaction chamber, the window being located entirely below a horizontal plane which is defined by a surface of a body to be etch treated; and

comparing said detected intensity to a predetermined threshold level.

2. A method as recited in claim 1, wherein during dry etching a plasma forms above the horizontal plane, and wherein said light emission detection is performed through the window which is located in the reaction chamber on a side opposite to that of the plasma.

3. A method as recited in claim 1, further comprising a step of controlling a temperature of the window.

4. A method as recited in claim 3, wherein the temperature of the window is raised and maintained at a predetermined value.