Residue treatment system, residue treatment method, and method of manufacturing semiconductor device

Abstract

This disclosure concerns a residue treatment system including a treatment tank which treats residue with etching fluid, the residue being generated in a trench formed in an insulating film by dry etching; a measurement unit which measures a characteristic amount of the etching fluid; and a control unit which calculates treatment time for removing the residue on the basis of a value obtained by measuring the characteristic amount, the control unit calculating the treatment time by using correlation between an etching rate of the insulating film and the characteristic amount.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an embodiment of a residue treatment system according to the present invention;

FIG. 2 is a first cross-sectional view showing an embodiment of a method of manufacturing semiconductor device according to the present invention;

FIG. 3 is a second cross-sectional view showing an embodiment of a method of manufacturing semiconductor device according to the present invention;

FIG. 4 is a third cross-sectional view showing an embodiment of a method of manufacturing semiconductor device according to the present invention;

FIG. 5 shows a relationship between a treatment time and an amount of etching for explaining an embodiment according to the present invention;

FIG. 6 shows a relationship between a treatment number of semiconductor wafers and an amount of etching for explaining an embodiment according to the present invention;

FIG. 7 shows a relationship between a characteristic and an amount of etching used for a residue treatment method of an embodiment according to the present invention;

FIG. 8 is a flowchart showing an embodiment of a residue treatment method according to the present invention; and

FIG. 9 shows a relationship between a characteristic amount and an amount of etching used for a residue treatment method of another embodiment according to the present invention.

Claims

1. A residue treatment system comprising: a treatment tank which treats residue with etching fluid, the residue being generated in a trench formed in an insulating film by dry etching;a measurement unit which measures a characteristic amount of the etching fluid; anda control unit which calculates treatment time for removing the residue on the basis of a value obtained by measuring the characteristic amount, the control unit calculating the treatment time by using correlation between an etching rate of the insulating film and the characteristic amount.

2. The residue treatment system according to claim 1, wherein a gas containing fluorine is used in the dry etching.

3. The residue treatment system according to claim 1, wherein the measurement unit measures pH of the etching fluid as the characteristic amount.

4. The residue treatment system according to claim 1, wherein the measurement unit measures a fluorine concentration of the etching fluid as the characteristic amount.

5. A residue treatment method comprising: measuring a value of a characteristic amount of a target etching fluid;calculating a target etching rate on the basis of the measured value by using correlation between the characteristic amount of a reference etching fluid and a reference etching rate of a reference insulating film, the correlation being obtained by etching the reference insulating film with the reference etching fluid; andcalculating treatment time for removing residue on the basis of the calculated target etching rate, the residue being generated in the trench formed by dry etching of a target insulating film.

6. The residue treatment method according to claim 5, wherein a gas containing fluorine is used in the dry etching.

7. The residue treatment method according to claim 5, wherein the measurement unit measures pH of the etching fluid as the characteristic amount.

8. The residue treatment method according to claim 5, wherein the measurement unit measures a fluorine concentration of the etching fluid as the characteristic amount.

9. The residue treatment method according to claim 5, wherein the time of the residue removal treatment is set so that a processing conversion difference is held constant, the processing conversion difference being a difference between an opening width of a trench or a via hole before the residue removal treatment and the opening width of the trench or the via hole after the residue removal treatment.

10. A method of manufacturing a semiconductor device comprising: depositing a target insulating film on a semiconductor substrate;selectively etching a part of the target insulating film by dry etching to form a trench;measuring a value obtained by measuring a characteristic amount of target etching fluid which removes residue generated in the trench;calculating treatment time for removing the residue on the basis of the measured value by using correlation between a characteristic amount of a reference etching fluid and a reference etching rate of a reference insulating film, the correlation being obtained by etching the reference insulating film with the reference etching fluid;removing the residue with the target etching fluid for the calculated treatment time.

11. The residue treatment method according to claim 10, wherein the measurement unit measures pH of the etching fluid as the characteristic amount.

12. The residue treatment method according to claim 10, wherein the measurement unit measures a fluorine concentration of the etching fluid as the characteristic amount.

13. The residue treatment method according to claim 10, wherein the time of the residue removal treatment is set so that a processing conversion difference is held constant, the processing conversion difference being a difference between an opening width of a trench or a via hole before the residue removal treatment and the opening width of the trench or the via hole after the residue removal treatment.