Semiconductor fabricating apparatus with function of determining etching processing state

• US 20040174530A1
• Filed: 03/04/2003
• Published: 09/09/2004
• Est. Priority Date: 03/04/2003
• Status: Active Grant

• Current Assignee: Hitachi High-Tech Company Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi High-Technologies Corporation (Hitachi, Ltd.)
• Inventors: Yoshigai, Motohiko, Usui, Tatehito, Ono, Tetsuo, Jyouo, Kazuhiro
• Granted Patent: US 6,972,848 B2
• Time in Patent Office: Days
• US Class Current: 356/504
• CPC Class Codes: H01J 37/32935 Monitoring and controlling tubes by information coming from the object and/or discharge
• CPC Class Codes: H01L 21/67069 for drying etching
• CPC Class Codes: H01L 21/67253 Process monitoring, e.g. flow or thickness monitoring

Abstract

When a semiconductor wafer placed in a chamber and having films thereon is etched using plasma generated in the chamber, a change in the amount of lights with at least two wavelengths, obtained from the wafer surface during the processing, is detected. The time between the time at which the amount of a light with one of two wavelengths is maximized and the time at which the amount of a light with the other wavelength is minimized is compared with a predetermined value to determine the state of etching processing.

Claims

1. A semiconductor fabricating apparatus etching a semiconductor wafer, placed in a chamber and having films thereon, using plasma generated in the chamber, said semiconductor fabricating apparatus comprising:

a detector that detects a change in an amount of light with at least two wavelengths obtained from a surface of the wafer for a predetermined time during the processing; and

a determination unit that compares an interval between a time at which an amount of light with one of the two wavelengths is maximized and a time at which an amount of light with the other wavelength is minimized with a predetermined value to determine a state of the etching.

2. The semiconductor fabricating apparatus according to claim 1, wherein said determination unit determines a thickness of the film being etched if the interval is determined to be smaller than the predetermined value.

3. The semiconductor fabricating apparatus according to claim 1, wherein said determination unit stops the etching processing if the interval is determined to be smaller than the predetermined value.

4. A semiconductor fabricating apparatus comprising:

a detector that, when a semiconductor wafer placed in a chamber is etched using plasma generated in the chamber, detects a light interference from a surface of the wafer for a predetermined time during the etching processing; and

a control unit that compares an interval between a time at which an amount of light with one of at least two wavelengths output from said detector is maximized and a time at which an amount of light with the other wavelength is minimized with a predetermined value to control the etching processing.

5. The semiconductor fabricating apparatus according to claim 4, wherein said control unit stops the etching processing if the interval is determined to be smaller than the predetermined value.

6. A semiconductor fabricating apparatus etching a semiconductor wafer, placed in a chamber and having a multiple-layer film composed of a first film formed a surface thereof and a second film formed on the first film, using plasma generated in the chamber, said semiconductor fabricating apparatus comprising:

a light detector that detects a change in an amount of light with a plurality of wavelengths obtained from a surface of the wafer for a predetermined time during which the second film is etched; and

a detection unit that detects a thickness of the first film based on a specific waveform obtained from an output of said detector.

7. The semiconductor fabricating apparatus according to claim 6, wherein, when said light detector detects, for the plurality of wavelengths, a change in an amount of interference light from the surface of the wafer with respect to time, said detection unit detects a characteristic change in an output of said light detector.

8. A semiconductor fabricating apparatus etching a semiconductor wafer, placed in a chamber and having a multiple-layer film composed of an oxide film formed a surface thereof and a film formed on the oxide film, using plasma generated in the chamber, said semiconductor fabricating apparatus comprising:

a light detector that detects an amount of light with a plurality of wavelengths obtained from a surface of the wafer for a predetermined time during which the film formed on the oxide film is etched; and

a detection unit that detects a thickness of the oxide film based on a specific waveform obtained from an output of said detector.

9. The semiconductor fabricating apparatus according to claim 8, wherein, when said light detector detects, for the plurality of wavelengths, a change in an amount of interference light from the surface of the wafer with respect to time, said detection unit detects a characteristic change in an output of said light detector.