Etching end point judging device

• US 20030036282A1
• Filed: 09/13/2002
• Published: 02/20/2003
• Est. Priority Date: 12/01/1998
• Status: Abandoned Application

• Current Assignee: Kazue Takahashi, Ken Yoshioka, Kouji Nishihata, Shigeru Nakamoto, Shoji Ikuhara, Tatehito Usui, Tetsunori Kaji
• Original Assignee: Kazue Takahashi, Ken Yoshioka, Kouji Nishihata, Shigeru Nakamoto, Shoji Ikuhara, Tatehito Usui, Tetsunori Kaji
• Inventors: Nishihata, Kouji, Usui, Tatehito, Nakamoto, Shigeru, Ikuhara, Shoji, Takahashi, Kazue, Yoshioka, Ken, Kaji, Tetsunori
• Application Number:
  US10/242,425
• Publication Number:
  US 20030036282A1
• Time in Patent Office: Days
• US Class Current: 438/708
• CPC Class Codes: H01L 21/76805 the opening being a via or contact hole penetrating the underlying conductor
• CPC Class Codes: H01L 21/76807 for dual damascene structures
• CPC Class Codes: H01L 21/76808 involving intermediate temporary filling with material
• CPC Class Codes: H01L 21/7681 involving one or more buried masks
• CPC Class Codes: H01L 21/76897 Formation of self-aligned vias or contact plugs, i.e. involving a lithographically uncritical step self-aligned silicidation on field effect transistors H01L29/665
• CPC Class Codes: H01L 22/26 Acting in response to an ongoing measurement without interruption of processing, e.g. endpoint detection, in-situ thickness measurement endpoint detection arrangements in CMP apparatus B24B37/013, in discharge apparatus H01J37/32
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

An etching end point judging device which uses emission spectroscopy for dry etching. The device includes an AND converter for obtaining time series data of emission intensity of a specific wavelength produced during etching, a first digital filter for performing smoothening of the time series data, a differential operator for obtaining a differential coefficient of the smoothened time series data, a second digital filter for smoothening the calculated differential coefficient of the time series data, and a discriminator for judging the etching end point by comparing said smoothened differential coefficient with a value set beforehand.

Claims

1. An etching end point judging device using emission spectroscopy for dry etching, wherein said device comprises A/D conversion means for obtaining time series data of emission intensity of a specific wavelength produced during etching, first digital filtering means for performing smoothening of said time series data, differential operation means for obtaining a differential coefficient of said smoothened time series data, second digital filtering means for smoothening the calculated differential coefficient of said time series data, and discrimination means for judging the etching end point by comparing said smoothened differential coefficient with a value set beforehand.

2. An etching end point judging device according to claim 1, wherein said device further comprises means for detecting abnormalities in the etching process, first digital filtering correction means that corrects—

in the event of detection of any abnormality—

said smoothened time series data, said differential coefficient time series data, and said smoothened differential coefficient time series data, correction means for correcting said differentiation operation, and second digital filtering correction means.

4. An etching end point judging device according to claim 1, wherein said device further comprises a photo-electronic photo-multiplier tube that outputs a current value that indicates the intensity of light of a specific wavelength that is emitted during etching carried out by a plasma discharge, an I/V converter that converts the current value output by the photo-multiplier tube into a voltage value, an A/D converter that digitizes the offset and gain for processing the output voltage from the I/V converter and the output from the output and gain of the IN converter, sense adjustment means that obtains from the data digitized in the A/D converter a sense voltage value for using the output of the photo-multiplier tube as a target output, dark current calculation means for determining the dark current of the photo-multiplier tube, gain correction means for changing the gain that is normally used as a fixed value in the event there is an overflow in the obtained sense voltage value, a D/A converter that converts the sense voltage value, offset value, and gain value that were obtained into analog data and sets the data.

3. An etching end point judging device that judges the end point of etching from a time series data of a differential coefficient of light emission intensity, wherein said device comprises display means that displays a transition of said time series data of said differential coefficient, and means for displaying an abnormality in the display of said time series data display of said differential coefficient in the event of detection of any abnormality.