Film thickness measuring method of member to be processed using emission spectroscopy and processing method of the member using the measuring method

• US 20020009814A1
• Filed: 03/05/2001
• Published: 01/24/2002
• Est. Priority Date: 06/20/2000
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Fujii, Takashi, Yoshigai, Motohiko, Usui, Tatehito, Kaji, Tetsunori
• Granted Patent: US 6,815,228 B2
• Time in Patent Office: Days
• US Class Current: 438/8
• CPC Class Codes: G01B 11/0625 with measurement of absorption or reflection
• CPC Class Codes: G01B 11/0675 using interferometry
• CPC Class Codes: H01L 21/67069 for drying etching
• 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: Y10T 436/106664 Blood serum or blood plasma standard or control

Abstract

A standard pattern of a differential value of an interference light is set with respect to a predetermined film thickness of a first member to be processed. The standard pattern uses a wavelength as a parameter. Then, an intensity of an interference light of a second member to be processed, composed just like the first member, is measured with respect to each of a plurality of wavelengths so as to obtain a real pattern of an differential value of the measured interference light intensity. The real pattern also uses a wavelength as a parameter. Then, the film thickness of the second member is obtained according to the standard pattern and the real pattern of the differential value.

Claims

1. A film thickness measuring method for measuring a film thickness of a member to be processed, comprising the steps of:

a) setting a standard pattern of a differential value of an interference light with respect to a predetermined film thickness of a first member to be processed, said standard pattern using a wavelength as a parameter;

b) measuring the intensity of an interference light of a second member to be processed, composed just like said first member, thereby obtaining a real pattern of a differential value of said measured interference light intensity, said real pattern using a wavelength as a parameter; and

c) obtaining a film thickness of said second member according to said standard pattern and said real pattern of said differential value.

2. The film thickness measuring method according to claim 1,

wherein said step c) compares a differential pattern having at least three wavelength ranges set so as to corresponded to a predetermined film thickness with a criterion value so that said predetermined film thickness of said member to be processed is obtained when said differential pattern having at least three wavelength ranges reaches said criterion value or under.

3. A processing method for a member to be processed, comprising the steps of:

setting a standard pattern of a differential value of an interference light with respect to a predetermined film thickness of a first member to be processed, said standard pattern using a wavelength as a parameter;

measuring the intensity of an interference light of a second member to be processed, composed just like said first member, with respect to each of a plurality of wavelengths so as to obtain a real pattern of said measured interference light intensity, said real pattern using a wavelength as a parameter;

obtaining a film thickness of said second member according to said standard pattern and said real pattern of said differential value; and

performing the next processing according to said obtained film thickness of said second member.

4. A method for etching a member to be processed, placed on a sample stand by plasma in a vacuum chamber, comprising the steps of:

setting a standard pattern of a differential value of an interference light with respect to a predetermined film thickness of a first member to be processed, said standard pattern using a wavelength as a parameter;

measuring the intensity of an interference light of a second member to be processed, composed just like said first member, with respect to each of a plurality of wavelengths so as to obtain a real pattern of said measured interference light intensity, said real pattern using a wavelength as a parameter;

obtaining a film thickness of said second member according to said standard pattern and said real pattern of said differential value; and

etching said second member while controlling the etching condition according to said obtained film thickness of said second member.

5. A method for measuring a film thickness of a member to be processed, comprising the steps of:

setting predetermined values of differential values of a wavelength at a zero-cross point and at least one more wavelength of an interference light with respect to a predetermined film thickness of a first member to be processed;

measuring the intensity of an interference light of a second member to be processed, composed just like said first member, with respect to each of a plurality of wavelengths so as to obtain a wavelength at a zero-cross point in a real pattern of a differential value of said measured interference light intensity and a differential value of a real pattern in at least one more wavelength; and

obtaining a film thickness of said second member according to matching of a wavelength at said zero-cross point between said standard pattern and said real pattern of said differential value and according to matching with a predetermined value of a differential value of at least one more wavelength.

6. A method for measuring a film thickness of a member to be processed, comprising the steps of:

setting a standard waveform pattern or a zero-cross waveform pattern of a differential value of an interference light with respect to a predetermined film thickness of a first member to be processed and with respect to each of a plurality of wavelengths;

measuring the intensity of an interference light of a second member to be processed, composed just like said first member, with respect to each of a plurality of wavelengths so as to obtain an actual waveform pattern or zero-cross waveform pattern of a differential value of each wavelength of said measured interference light intensity; and

comparing said standard pattern with said actual pattern so as to obtain a film thickness of said second member.

7. A method for measuring a film thickness of a member to be processed, comprising the steps of:

selecting specific wavelengths of an interference light of a second member to be processed, as guide and target wavelengths;

obtaining a film thickness range of said second member from a guide wavelength differential value zero-cross pattern of an interference light of a first member to be processed, composed just like said second member, according to said guide wavelength with respect to a predetermined film thickness;

obtaining a film thickness of said second member within said film thickness range from a zero-cross waveform pattern of said differential value of said interference light intensity having said target wavelength.

8. A film thickness measuring apparatus for measuring a film thickness of a member to be processed, comprising:

a differential waveform pattern data base for holding a standard pattern of a differential value of an interference light with respect a predetermined film thickness of a first member to be processed, said standard pattern using a wavelength as a parameter;

a spectroscope for measuring the intensity of an interference light of a second member to be processed, composed just like said first member, with respect to each of a plurality of wavelengths;

a differentiator for obtaining a real pattern of a differential value of said measured interference light intensity, said real pattern using a wavelength as a parameter; and

a unit for obtaining a film thickness of said second member according to said standard pattern and said real pattern of said differential value.

9. A film thickness measuring apparatus for measuring a film thickness of a member to be processed, comprising:

a differential waveform pattern data base for holding predetermined differential values of a wavelength at a zero-cross point and at least one more wavelength of an interference light with respect to a predetermined film thickness of a first member to be processed;

a spectroscope for measuring the intensity of an interference light of a second member to be processed, composed just like said first member, with respect to each of a plurality of wavelengths;

a differentiator for obtaining a wavelength at a zero-cross point in a real pattern of a differential value of said measured interference light intensity and a differential value of a real pattern in at least one more wavelength; and

a unit for obtaining a film thickness of said second member according to matching of a wavelength at said zero-cross point between said standard pattern and said real pattern of said differential value and according to matching with a predetermined value of a differential value in at least one more wavelength.

10. A processing apparatus for processing a member to be processed, comprising:

a unit for setting a standard pattern of a differential value of an interference light with respect to a predetermined film thickness of a first member to be processed, said standard pattern using a wavelength as a parameter;

a unit for measuring the intensity of an interference light of a second member to be processed, composed just like said first member, with respect to each of a plurality of wavelengths so as to obtain a real pattern of a differential value of said measured interference light intensity, said real pattern using a wavelength as a parameter;

a unit for obtaining a film thickness of said second member according to said standard pattern and said real pattern of said differential value; and

a unit for performing the next processing according to said obtained film thickness of said second member.

11. An etching apparatus for etching a member to be processed placed on a sample stand by plasma in a vacuum chamber, comprising:

a unit for setting a standard pattern of a differential value of an interference light with respect to a predetermined film thickness of a first member to be processed, said standard pattern using a wavelength as a parameter;

a unit for measuring the intensity of an interference light of a second member to be processed, composed just like said first member, so as to obtain a real pattern of a differential value of said measured interference light intensity, said real pattern using a wavelength as a parameter;

a unit for obtaining a film thickness of said second member according to said standard pattern and said real pattern of said differential value; and

a unit for etching said second member while controlling etching conditions according to said obtained film thickness of said second member.