Cleaning method

• US 9,553,004 B2
• Filed: 09/29/2010
• Issued: 01/24/2017
• Est. Priority Date: 12/14/2009
• Status: Active Grant

• Current Assignee: Sumco Corporation
• Original Assignee: Sumco Corporation
• Inventors: Takemura, Makoto, Mori, Keiichiro
• Primary Examiner(s): Kornakov, Michael
• Assistant Examiner(s): CAMPBELL, NATASHA N.
• Application Number:
  US13/512,735
• Publication Number:
  US 20120234358A1
• Time in Patent Office: 2,309 Days
• Field of Search: 134/26
• US Class Current: 1/1
• CPC Class Codes: B08B 3/04 Cleaning involving contact with liquid
• CPC Class Codes: H01L 21/02052 Wet cleaning only H01L21/02085 takes precedence
• CPC Class Codes: H01L 21/67057 with the semiconductor substrates being dipped in baths or vessels

Abstract

To provide a cleaning method which makes it possible to reduce alkaline component mixing in an ozone cleaning solution, thereby preventing impairment of cleaning ability of ozone. In the cleaning method, before chuck members retain another workpiece having previously been dipped in an ozone cleaning solution in an ozone cleaning tank, alkaline component attached to part of transfer arms and the chuck members is removed by cleaning, thereby preventing the alkaline component from mixing into the ozone cleaning solution.

Claims

1. A method of cleaning a plurality of workpieces using a cleaning apparatus having a plurality of cleaning tanks including an ozone cleaning tank filled with an ozone cleaning solution and an alkaline cleaning tank filled with a solution containing an alkaline component, and a transfer means having transfer arms and chuck members provided on the transfer arms, which is movable between the plurality of cleaning tanks, comprising:

with one workpiece of a plurality of workpieces being detachably retained by the chuck members, dipping the workpiece into a cleaning solution in one of the plurality of cleaning tanks at least together with the chuck members and part of the transfer arms;

then detaching the chuck members from the workpiece to move the transfer means during treatment of the workpiece in the cleaning tank;

detachably retaining another workpiece having been dipped in a cleaning solution of another cleaning tank using the chuck members; and

treating the plurality of workpieces sequentially in each of the ozone cleaning tank and alkaline cleaning tank by transferring the workpieces with the transfer means from the ozone cleaning tank to the alkaline cleaning tank, wherein directly before the chuck members retain each of the plurality of workpieces from the ozone cleaning tank for transferring the retained workpiece to an alkaline tank, alkaline component attached to part of the transfer arms and the chuck members is removed by cleaning, thereby preventing the alkaline component from mixing into the ozone cleaning solution, and wherein during the cleaning of the plurality of workpieces there is at least one step of transferring a workpiece from the alkaline tank that is not directly preceded by a cleaning step of the transfer arms and the chuck members,

wherein the cleaning apparatus further includes a pure water cleaning tank for workpieces, filled with purified water for cleaning the workpiece,

the transfer arms and the chuck members are cleaned by being dipped in and then being pulled out of the purified water in the pure water cleaning tank for workpieces, and

the transfer arms and the chuck members are pulled out at a rate of 300 mm/sec or less after being dipped in the pure water cleaning tank.

2. The cleaning method according to claim 1,

wherein the cleaning apparatus further includes a pure water cleaning tank for chuck members, filled with the purified water for cleaning the transfer arms and the chuck members, and

the transfer arms and the chuck members are cleaned by being dipped in and then being pulled out of purified water in the pure water cleaning tank for chuck members and by further spraying the transfer arms and the chuck members with purified water during the pullout.

3. The cleaning method according to claim 1, wherein a concentration of ozone in the ozone cleaning solution after the transfer arms and the chuck members dipped at least once in the solution containing an alkaline component in the alkaline cleaning tank are dipped in the ozone cleaning solution is 3 ppm or more.

4. The cleaning method according to claim 1, wherein the workpiece is one or a plurality of wafers, or a plurality of wafers stored in a receiver cassette.

6. The cleaning method according to claim 1, wherein the pull-out rate is from 100 mm/sec to 300 mm/sec.

5. A method of cleaning a plurality of workpieces using a cleaning apparatus having a plurality of cleaning tanks including at least an ozone cleaning tank filled with an ozone cleaning solution and an alkaline cleaning tank filled with a solution containing an alkaline component, and a transfer means having transfer arms and chuck members provided on the transfer arms, which is movable between the plurality of cleaning tanks, comprising:

with one workpiece of a plurality of workpieces being detachably retained by the chuck members, dipping the workpiece into the solution containing the alkaline component in the alkaline cleaning tank at least together with the chuck members and part of the transfer arms;

then detaching the chuck members from the workpiece to move the transfer means during treatment of the workpiece in the cleaning tank; and

detachably retaining an other workpiece having been dipped in the ozone cleaning solution of the ozone cleaning tank using the chuck members and transferring the other workpiece to the alkaline cleaning tank,

wherein directly before the chuck members retain the other workpiece from the ozone cleaning tank for transferring the retained workpiece to an alkaline tank, alkaline component attached to part of the transfer arms and the chuck members is removed by cleaning, thereby preventing the alkaline component from mixing into the ozone cleaning solution, and wherein during the cleaning of the plurality of workpieces there is at least one step of transferring a workpiece from the alkaline tank that is not directly preceded by a cleaning step of the transfer arms and the chuck members,

wherein the cleaning apparatus further includes a pure water cleaning tank for workpieces, filled with purified water for cleaning the workpiece,

the transfer arms and the chuck members are cleaned by being dipped in and then being pulled out of the purified water in the pure water cleaning tank for workpieces, and

the transfer arms and the chuck members are pulled out at a rate of 300 mm/sec or less after being dipped in the pure water cleaning tank.

7. The cleaning method according to claim 5, wherein the pull-out rate is from 100 mm/sec to 300 mm/sec.