Method for forming shallow trench isolation of semiconductor device
View Patent ↗A shallow trench isolation well is formed to be very thin in a highly integrated semiconductor device. When critical dimension (CD) is small, it is difficult to reduce the width of the photosensitive layer pattern for forming a trench to no more than a predetermined value due to limitations on the photolithography process.
1. A method comprising:
forming a photosensitive layer pattern over a semiconductor;
forming a copper layer over the substrate where the photosensitive layer pattern is formed;
planarizing the copper layer using a CMP process until a surface of the photosensitive layer pattern is exposed;
removing the photosensitive layer pattern; and
etching the substrate using the copper layer as a mask to form a trench.
2. The method of claim 1 , wherein the removal of the photosensitive layer pattern is performed by a wet etching process.
3. The method of claim 2 , wherein the wet etching process is performed using one of an SC- 1 and an SC- 2 cleansing solution.
4. The method of claim 1 , further including removing the copper layer on the substrate.
5. A method of forming an isolation trench of a semiconductor device comprising:
forming a photosensitive layer pattern over a semiconductor substrate using a photolithography process;
forming a copper layer over the substrate where the photosensitive layer pattern is formed;
planarizing the copper layer using a CMP process until a surface of the photosensitive layer pattern is exposed;
removing the photosensitive layer pattern through a wet etching process;
etching the substrate using the copper layer as a mask to form a trench;
removing the copper layer on the substrate;
forming a trench oxide layer over the substrate where the trench is formed; and
planarizing the trench oxide layer using the CMP process.
6. The method of claim 5 , wherein the copper layer is formed using an electro-chemical plating (ECP) method.
7. The method of claim 5 , wherein the wet etching process is performed using SC- 1 or SC- 2 cleansing solution.