Method for manufacturing semiconductor device
A method for manufacturing a semiconductor device makes it possible to efficiently polish with a polishing tape a peripheral portion of a silicon substrate under polishing conditions particularly suited for a deposited film and for silicon underlying the deposited film. The method includes pressing a first polishing tape against a peripheral portion of a device substrate having a deposited film on a silicon surface while rotating the device substrate at a first rotational speed, thereby removing the deposited film lying in the peripheral portion of the device substrate and exposing the underlying silicon. A second polishing tape is pressed against the exposed silicon lying in the peripheral portion of the device substrate while rotating the device substrate at a second rotational speed, thereby polishing the silicon to a predetermined depth.
1. A method for manufacturing a semiconductor device comprising:
pressing a first polishing tape against a peripheral portion of a device substrate having a deposited film on a silicon substrate while rotating the device substrate at a first rotational speed, thereby removing the deposited film lying in the peripheral portion of the device substrate and exposing the underlying silicon; and then
pressing a second polishing tape against the exposed silicon lying in the peripheral portion of the device substrate while rotating the device substrate at a second rotational speed, the second rotational speed being different from the first rotational speed, thereby polishing the silicon substrate to a predetermined depth.
2. The method for manufacturing a semiconductor device according to claim 1 , wherein the first rotational speed is 100 to 400 rpm, and the second rotational speed is not less than 500 rpm.
3. The method for manufacturing a semiconductor device according to claim 1 , wherein the first polishing tape is a diamond tape having #2000 or less diamond abrasive particles or ceria tape having ceria abrasive particles, and the second polishing tape is a diamond tape having #4000-#20000 diamond abrasive particles.
4. The method for manufacturing a semiconductor device according to claim 1 , further comprising:
bonding a supporting substrate to the surface of the device substrate after polishing the silicon to a predetermined depth;
grinding silicon on the back side of the device substrate until a predetermined thickness of the device substrate is reached; and then
pressing a third polishing tape against a peripheral portion of the supporting substrate while rotating the bonded substrates at a third rotational speed, thereby polishing silicon, lying in the peripheral portion of the supporting substrate, to a predetermined depth to form a chamfered portion.
5. The method for manufacturing a semiconductor device according to claim 4 , further comprising:
pressing a fourth polishing tape against the chamfered portion formed in the peripheral portion of the supporting substrate while rotating the bonded substrates at a fourth rotational speed to carry out finish polishing of the chamfered portion.
6. The method for manufacturing a semiconductor device according to claim 1 , wherein the second rotational speed is greater than the first rotational speed.