Determining method of thermal processing condition

• US 6,787,377 B2
• Filed: 01/24/2003
• Issued: 09/07/2004
• Est. Priority Date: 07/25/2000
• Status: Expired due to Term

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Wang, Wenling, Suzuki, Fujio, Sakamoto, Koichi, Yasuhara, Moyuru
• Primary Examiner(s): Thompson, Craig A.
• Assistant Examiner(s): Berezny, Nema
• Application Number:
  US10/333,585
• Publication Number:
  US 20030109071A1
• Time in Patent Office: 592 Days
• Field of Search: 438/14, 438/907, 438/909, 438/935, 374/102, 374/137
• US Class Current: 438/14
• CPC Class Codes: H01L 21/0217 the material being a silicon nitride not containing oxygen, e.g. SixNy or SixByNz H01L21/02126 and H01L21/0214 take precedence
• CPC Class Codes: H01L 21/3185 of siliconnitrides
• CPC Class Codes: H01L 21/324 Thermal treatment for modifying the properties of semiconductor bodies, e.g. annealing, sintering H01L21/20 - H01L21/288 and H01L21/302 - H01L21/322 take precedence
• CPC Class Codes: H01L 22/20 Sequence of activities consisting of a plurality of measurements, corrections, marking or sorting steps
• CPC Class Codes: Y10S 438/907 Continuous processing
• CPC Class Codes: Y10S 438/909 Controlled atmosphere
• CPC Class Codes: Y10S 438/935 Gas flow control

Abstract

The invention is a method of determining a set temperature profile for a method of controlling respective substrate temperatures of a plurality of groups in accordance with respective corresponding set temperature profiles, in a method of heat processing a plurality of substrates that are classified into the plurality of groups. The invention includes a first heat processing step of controlling respective substrate temperatures of a plurality of groups in accordance with respective predetermined provisional set temperature profiles for first-batch substrates that are classified into the plurality of groups, and of introducing a process gas to conduct a heat process to form films on the substrates; a first film-thickness measuring step of measuring a thickness of the films formed on the substrates; and a first set-temperature-profile amending step of respectively amending the provisional set temperature profiles based on the measured thickness, in such a manner that a thickness of films formed during a heat process is substantially the same between the plurality of groups. In the first heat processing step, the provisional set temperature profiles are profiles whose set temperatures change as time passes.

Claims

1. A method of determining a set temperature profile for a method of controlling respective substrate temperatures of a plurality of groups in accordance with respective corresponding set temperature profiles, in a method of heat processing a plurality of substrates that are classified into the plurality of groups, the method of determining a set temperature profile comprising;

a first heat processing step of controlling respective substrate temperatures of a plurality of groups in accordance with respective predetermined provisional set temperature profiles for first-batch substrates that are classified into the plurality of groups, and of introducing a process gas to conduct a heat process to form films on the substrates;

a first film-thickness measuring step of measuring a thickness of the films formed on the substrates; and

a first set-temperature-profile amending step of respectively amending the provisional set temperature profiles based on the measured thickness, in such a manner that a thickness of films formed during a heat process is substantially the same between the plurality of groups;

wherein, in the first heat processing step, the provisional set temperature profiles are profiles whose set temperatures change as time passes.

2. A method of determining a set temperature profile according to claim 1, wherein:

in the first heat processing step,

set temperatures of the provisional set temperature profiles have a substantially constant gradient with respect to time.

3. A method of determining a set temperature profile according to claim 1, wherein:

in the first film-thickness measuring step,

for at least one substrate in each of the plurality of groups,

film thickness is measured at a plurality of points of each substrate, and

an average of the measured values is obtained as a film thickness of the substrate.

4. A method of determining a set temperature profile according to claim 1, wherein;

in the first set-temperature-profile amending step,

averages of ideal set temperatures to be amended are calculated based on a thickness-temperature dependant relationship between the substrate temperatures and the film thickness, and

the provisional set temperature profiles are amended based on the averages.

5. A method of determining a set temperature profile according to claim 1, further comprising after the first set-temperature-profile amending step;

a second heat processing step of controlling the respective substrate temperatures of the plurality of groups in accordance with respective amended first set temperature profiles for second-batch substrates that are classified into the plurality of groups, and of introducing a process gas to conduct a heat process to form films on the substrates;

a second film-thickness measuring step of measuring a thickness of the films formed on the substrates; and

a second set-temperature-profile amending step of respectively amending the first set temperature profiles based on the measured thickness, in such a manner that a thickness of films formed during a heat process is substantially the same between the plurality of groups.

6. A method of determining a set temperature profile according to claim 5, wherein:

in the second set-temperature-profile amending step,

averages of ideal set temperatures to be amended are calculated based on a thickness-temperature dependant relationship between the substrate temperatures and the film thickness, and

the first set temperature profiles are amended based on the averages.

7. A method of determining a set temperature profile according to claim 6, wherein:

in the second set-temperature-profile amending step,

the thickness-temperature dependant relationship between the substrate temperatures and the film thickness is amended based on averages in time of the provisional set temperature profiles during the first heat processing step, film thickness of the films on the first-batch substrates, averages in time of the first set temperature profiles during the second heat processing step, and film thickness of the films on the second-batch substrates.

8. A method of determining a set temperature profile according to claim 5, wherein:

the second heat processing step, the second film-thickness measuring step and the second set-temperature-profile amending step are repeated at least twice in order thereof.

9. A method of determining a set temperature profile according to claim 5, wherein:

the second heat processing step, the second film-thickness measuring step and the second set-temperature-profile amending step are repeated at least twice in order thereof.

10. A method of determining a set temperature profile for a method of controlling respective substrate temperatures of a plurality of groups in accordance with respective corresponding set temperature profiles, in a method of heat processing a plurality of substrates that are classified into the plurality of groups, the method of determining a set temperature profile comprising;

a first set-temperature-profile determining step of determining first set temperature profiles, each of which is set for each of a plurality of groups of substrates, in accordance with which films of substantially the same thickness between the plurality of groups are formed on the substrates when a process gas is introduced to conduct a heat process, and whose set temperatures don'"'"'t change as time passes during the heat process,

a second set-temperature-profile determining step of determining second set temperature profiles, each of which is set for each of the plurality of groups of the substrates by amending each first set temperature profile, in accordance with which a film of substantially the same thickness is formed on each of the substrates when a process gas is introduced to conduct a heat process, and whose set temperatures change as time passes during the heat process, and

a third set-temperature-profile determining step of determining third set temperature profiles, each of which is set for each of the plurality of groups of the substrates by amending each second set temperature profile, in accordance with which films of substantially the same thickness between the plurality of groups are formed on the substrates when a process gas is introduced to conduct a heat process, and whose set temperatures change as time passes during the heat process.

11. A method of determining a set temperature profile according to claim 10, wherein:

the first set-temperature-profile determining step includes;

a first heat processing step of controlling respective substrate temperatures of the plurality of groups in accordance with respective predetermined provisional set temperature profiles for first-batch substrates that are classified into the plurality of groups, and of introducing a process gas to conduct a heat process to form films on the substrates;

a first film-thickness measuring step of measuring a thickness of the films formed on the substrates; and

a first set-temperature-profile amending step of calculating ideal constant set temperatures based on the measured thickness, in such a manner that a thickness of films formed during a heat process is substantially the same between the plurality of groups, and of respectively amending the provisional set temperature profiles based on the ideal constant set temperatures.

12. A method of determining a set temperature profile according to claim 11, wherein;

in the first set-temperature-profile amending step,

the ideal constant set temperatures are calculated based on a thickness-temperature dependant relationship between the substrate temperatures and the film thickness.

13. A method of determining a set temperature profile according to claim 12, wherein:

in the first film-thickness measuring step,

for at least one substrate in each of the plurality of groups,

film thickness is measured at a plurality of points of each substrate, and

an average of the measured values is obtained as a film thickness of the substrate.

14. A method of determining a set temperature profile according to claim 11, wherein:

the first set-temperature-profile determining step includes after the first set-temperature-profile amending step;

a second heat processing step of controlling the respective substrate temperatures of the plurality of groups in accordance with respective amended provisional set temperature profiles for second-batch substrates that are classified into the plurality of groups, and of introducing a process gas to conduct a heat process to form films on the substrates;

a second film-thickness measuring step of measuring a thickness of the films formed on the substrates; and

a second set-temperature-profile amending step of calculating again ideal constant set temperatures based on the measured thickness, in such a manner that a thickness of films formed during a heat process is substantially the same between the plurality of groups, and of respectively amending again the amended provisional set temperature profiles based on the ideal constant set temperatures.

15. A method of determining a set temperature profile according to claim 14, wherein;

in the second set-temperature-profile amending step,

the ideal constant Bet temperatures are calculated again based on a thickness-temperature dependant relationship between the substrate temperatures and the film thickness.

16. A method of determining a set temperature profile according to claim 15, wherein:

in the second set-temperature-profile amending step,

the thickness-temperature dependant relationship between the substrate temperatures and the film thickness is amended based on set temperatures of the provisional set temperature profiles during the first heat processing step, film thickness of the films on the first-batch substrates, set temperatures of the amended provisional set temperature profiles during the second heat processing step, and film thickness of the films on the second-batch substrates.

17. A method of determining a set temperature profile according to claim 11, wherein:

the third set-temperature-profile determining step includes;

a fifth heat processing step of controlling respective substrate temperatures of the plurality of groups in accordance with the respective second set temperature profiles for fifth-batch substrates that are classified into the plurality of groups, and of introducing a process gas to conduct a heat process to form films on the substrates;

a fifth film-thickness measuring step of measuring a thickness of the films formed on the substrates; and

a fifth set-temperature-profile amending step of calculating averages of set temperatures based on the measured thickness, in such a manner that a thickness of films formed during a heat process is substantially the same between the plurality of groups, and of respectively amending the second set temperature profiles based on the averages of set temperatures.

18. A method of determining a set temperature profile according to claim 10, wherein:

averages in time of set temperatures of the second set temperature profiles during the heat process are substantially the same as constant set temperatures of the first set temperature profiles during the heat process.

19. A method of determining a set temperature profile according to claim 10, wherein:

set temperatures of the second set temperature profiles during the heat process have a substantially constant gradient with respect to time.

20. A method of determining a set temperature profile according to claim 10, wherein:

the second set-temperature-profile determining step includes;

a third heat processing step of controlling respective substrate temperatures of the plurality of groups in accordance with the respective first set temperature profiles for third-batch substrates that are classified into the plurality of groups, and of introducing a process gas to conduct a heat process to form films on the substrates;

a third film-thickness measuring step of measuring a thickness distribution of the films formed on the substrates; and

a third set-temperature-profile amending step of respectively amending the first set temperature profiles based on the measured thickness distribution.

21. A method of determining a set temperature profile according to claim 20, wherein:

the third film-thickness measuring step includes;

a step of measuring a film thickness on the substrate near a central portion thereof, and

a step of measuring a film thickness on the substrate near a plurality of peripheral portions thereof.

22. A method of determining a set temperature profile according to claim 20, wherein:

the third film-thickness measuring step includes;

a step of obtaining the thickness distribution on the substrates as a function of a distance from a substantially center thereof.

23. A method of determining a set temperature profile according to claim 22, wherein:

the function is a function of a square of the distance from the substantially center thereof.

24. A method of determining a set temperature profile according to claim 20, wherein:

the third film-thickness measuring step includes;

a step of obtaining the thickness distribution on the substrates as a difference between a film thickness near a central portion thereof and a film thickness near a peripheral portion thereof.

25. A method of determining a set temperature profile according to claim 20, wherein:

in the third set-temperature-profile amending step,

a necessary temperature distribution in one substrate that is necessary for forming a film whose thickness is substantially uniform within a surface of the substrate is adapted to be calculated based on a thickness-temperature dependant relationship between the substrate temperatures and the film thickness and the measured thickness distribution.

26. A method of determining a set temperature profile according to claim 25, wherein:

the necessary temperature distribution is represented by a difference between a temperature of the substrate near a central portion thereof and a temperature of the substrate near a peripheral portion thereof.

27. A method of determining a set temperature profile according to claim 25, wherein:

in the third set-temperature-profile amending step,

necessary gradients with respect to time of set temperature profiles to be obtained by amended are calculated based on a dependant relationship between gradients with respect to time of set temperature profiles and temperature distribution within the substrate and the necessary temperature distribution, and

the first set temperature profiles are adapted to be amended based on the necessary gradients.

28. A method of determining a set temperature profile according to claim 20, wherein:

the second set-temperature-profile determining step includes after the third set-temperature-profile amending step;

a fourth heat processing step of controlling the respective substrate temperatures of the plurality of groups in accordance with respective amended first set temperature profiles for fourth-batch substrates that are classified into the plurality of groups, and of introducing a process gas to conduct a heat process to form films on the substrates;

a fourth film-thickness measuring step of measuring a thickness distribution of the films formed on the substrates; and

a fourth set-temperature-profile amending step of respectively amending again the amended first set temperature profiles based on the measured thickness distribution.

29. A method of determining a set temperature profile according to claim 28, wherein:

in the fourth set-temperature-profile amending step,

a necessary temperature distribution in one substrate that is necessary for forming a film whose thickness is substantially uniform within a surface of the substrate is adapted to be calculated based on a thickness-temperature dependant relationship between the substrate temperatures and the film thickness and the measured thickness distribution.

30. A method of determining a set temperature profile according to claim 29, wherein:

in the fourth set-temperature-profile amending step,

the thickness-temperature dependant relationship between the substrate temperatures and the film thickness is amended based on averages in time of the first set temperature profiles during the third heat processing step, film thickness of the films on the third-batch substrates, averages in time of the amended first set temperature profiles during the fourth heat processing step, and film thickness of the films on the fourth-batch substrates.

31. A method of determining a set temperature profile according to claim 28, wherein:

the fourth heat processing step, the fourth film-thickness measuring step and the fourth set-temperature-profile amending step are repeated at least twice in order thereof.