Semiconductor substrate cleaning method and semiconductor substrate cleaning machine

Abstract

A semiconductor substrate cleaning method includes a first cleaning step of cleaning the surface of a semiconductor substrate with the use of a first brush and a second cleaning step of cleaning the surface of the semiconductor substrate with the use of a second brush after the first cleaning step. The second cleaning step is performed under a condition that suppresses recontamination of the surface of the semiconductor substrate in comparison with the first cleaning step.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flowchart depicting a flow of a semiconductor substrate cleaning method according to Embodiment 1.

FIG. 2 is a perspective view showing a positional relationship between a semiconductor substrate and a cylindrical brush in the semiconductor substrate cleaning method according to Embodiment 1.

FIG. 3 is an illustration showing a semiconductor substrate cleaning machine according to Embodiment 1 in a state before cleaning in FIG. 1.

FIG. 4 is an illustration showing a first brush cleaning step at a high pressing pressure of the brush in the semiconductor substrate cleaning method according to Embodiment 1.

FIG. 5 is an illustration showing a second brush cleaning step at a low pressing pressure of the brush in the semiconductor substrate cleaning method according to Embodiment 1.

FIG. 6 is a flowchart depicting a flow of a semiconductor substrate cleaning method according to Embodiment 2.

FIG. 7 is an illustration showing a first brush cleaning step in which a brush is arranged close to a semiconductor substrate in the semiconductor substrate cleaning method according to Embodiment 2.

FIG. 8 an illustration showing a second brush cleaning step in which the brush is arranged far from the semiconductor substrate in the semiconductor substrate cleaning method according to Embodiment 2.

FIG. 9 is a flowchart depicting a flow of a semiconductor substrate cleaning method according to Embodiment 3.

FIG. 10 is an illustration showing a semiconductor substrate cleaning machine according to Embodiment 3 in a state before cleaning in FIG. 9.

FIG. 11 is an illustration showing a first brush cleaning step using a brush having a large outer diameter in the semiconductor substrate cleaning method according to Embodiment 3.

FIG. 12 is an illustration showing a second brush cleaning step using a brush having a small outer diameter in the semiconductor substrate cleaning method according to Embodiment 3.

FIG. 13 is a flowchart depicting a flow of a semiconductor substrate cleaning method according to Embodiment 4.

FIG. 14 is an illustration showing a semiconductor substrate cleaning machine according to Embodiment 4 in a state before cleaning in FIG. 13.

FIG. 15 is an illustration showing a first brush cleaning step using a brush having a high hardness in the semiconductor substrate cleaning method according to Embodiment 4.

FIG. 16 is an illustration showing a second brush cleaning step using a brush having a low hardness in the semiconductor substrate cleaning method according to Embodiment 4.

FIG. 17 is a flowchart depicting a flow of a semiconductor substrate cleaning method according to Embodiment 5.

FIG. 18 is an illustration showing a semiconductor substrate cleaning machine according to Embodiment 5 in a state before cleaning in FIG. 17.

FIG. 19 is an illustration showing a first brush cleaning step using a brush including tall protrusions in the semiconductor substrate cleaning method according to Embodiment 5.

FIG. 20 is an illustration showing a second brush cleaning step using a brush including short protrusions in the semiconductor substrate cleaning method according to Embodiment 5.

FIG. 21 is an illustration schematically showing a two-stage semiconductor substrate cleaning machine according to Embodiment 6.

FIG. 22 is a flowchart depicting a flow of a semiconductor substrate cleaning method in Example 1 according to Embodiment 6.

FIG. 23 is a flowchart depicting a flow of a semiconductor substrate cleaning method in Example 2 according to Embodiment 6.

FIG. 24 is a flowchart depicting a flow of a semiconductor substrate cleaning method in Example 3 according to Embodiment 6.

FIG. 25 is a flowchart depicting a flow of a semiconductor substrate cleaning method in Example 4 according to Embodiment 6.

FIG. 26 is a flowchart depicting a flow of a semiconductor substrate cleaning method in Example 5 according to Embodiment 6.

FIG. 27 is an illustration showing a conventional semiconductor substrate cleaning machine using a cup-shaped (disk-shaped) brush.

FIG. 28 is an illustration showing a conventional semiconductor substrate cleaning machine using a cylindrical brush.

FIG. 29 is a flowchart depicting a flow of a conventional semiconductor substrate cleaning method.

FIG. 30 is an illustration showing a cleaning state in the conventional semiconductor substrate cleaning method.

Claims

1. A semiconductor substrate cleaning method comprising: a first cleaning step of cleaning the surface of a semiconductor substrate with the use of a first brush; anda second cleaning step of cleaning, after the first cleaning step, the surface of the semiconductor substrate with the use of a second brush under a condition that suppresses recontamination of the surface of the semiconductor substrate in comparison with the first cleaning step.

2. The semiconductor substrate cleaning method of claim 1, wherein the first brush is identical with the second brush.

3. The semiconductor substrate cleaning method of claim 1, wherein a pressing pressure of the second brush against the semiconductor substrate in the second cleaning step is lower than a pressing pressure of the first brush against the semiconductor substrate in the first cleaning step.

4. The semiconductor substrate cleaning method of claim 1, wherein the position of the second brush in the second cleaning step is farther than the position of the first brush in the first cleaning step relative to the semiconductor substrate.

5. The semiconductor substrate cleaning method of claim 1, wherein the first brush and the second brush are cylindrical, andthe diameter of the second brush is smaller than the diameter of the first brush.

6. The semiconductor substrate cleaning method of claim 1, wherein the second brush is made of a material softer than the first brush.

7. The semiconductor substrate cleaning method of claim 1, wherein each of the first brush and the second brush includes a brush main body and protrusions provided at the surface of the brush main body, andthe height of the protrusions of the second brush is smaller than the height of the protrusions of the first brush.

8. The semiconductor substrate cleaning method of claim 1, wherein the first cleaning step and the second cleaning step are performed by a single cleaning machine.

9. The semiconductor substrate cleaning method of claim 1, wherein the first cleaning step and the second cleaning step are performed by separate cleaning machines.

10. The semiconductor substrate cleaning method of claim 1, wherein diluted hydrofluoric acid, ammonium water, organic acid, or functional water is used as a cleaning solution.

11. The semiconductor substrate cleaning method of claim 1, wherein the first brush and the second brush are made of a macromolecular material.

12. A semiconductor substrate cleaning machine comprising: a first brush for cleaning the surface of a semiconductor substrate; anda second brush for cleaning the surface of the semiconductor substrate,wherein cleaning by the second brush is performed under a condition that suppresses recontamination of the surface of the semiconductor substrate in comparison with the first cleaning step.

13. The semiconductor substrate cleaning machine of claim 12, wherein the first brush and the second brush are cylindrical, andthe diameter of the second brush is smaller than the diameter of the first brush.

14. The semiconductor substrate cleaning machine of claim 12, wherein the second brush is made of a material softer than the first brush.

15. The semiconductor substrate cleaning machine of claim 12, wherein each of the first brush and the second brush includes a brush main body and protrusions provided at the surface of the brush main body, andthe height of the protrusions of the second brush is smaller than the height of the protrusions of the first brush.