Method of making semiconductor devices
View Patent ↗A method for fabricating semiconductor device is provided. A high stress layer formed on, under or on both sides of the transistors of the semiconductor device is employed as a cap layer. A specific region is then defined through photo resistor mask, and the stress of the region is changed by ion implanting. Therefore, compressive stress and tensile stress occur on the high stress layer. According the disclosed method, the high stress layer may simultaneously improve the characteristics of the transistors formed on the same wafer. Further, the mobility of the carriers of the device is enhanced.
1. A method of making a semiconductor device, comprising the steps of:
providing a silicon substrate;
forming a semiconductor device on the silicon substrate;
forming at least one first high stress layer under the silicon substrate and at least one second high stress layer on the semiconductor device simultaneously using a single process;
coating photo resist on one region of the second high stress layer; and
performing ion implantation on the part of the semiconductor device that is not covered by the photo resist.
2. The method of claim 1 , wherein the semiconductor device has a plurality of PMOS and a plurality of NMOS.
3. The method of claim 1 , wherein the semiconductor device has a plurality of PMOS.
4. The method of claim 1 , wherein the semiconductor device has a plurality of NMOS.
5. The method of claim 1 , wherein the material of the high stress layer is selected from the group consisting of silicon nitride, TEOS, BPSG, PSG, BSG, SiO2, and SiO x N y .
6. The method of claim 1 , wherein the high stress layer is formed using a method selected from plasma enhanced chemical vapor deposition (PECVD) and low pressure chemical vapor deposition (LPCVD).
7. The method of claim 1 , wherein the implanted ion is selected from the group consisting of the elements P, As, Sb, the compound BF 2 , and a combination of them in arbitrary proportion.
8. The method of claim 1 , wherein the ion implantation depth is between 5% and 90% of the thickness of the high stress layer.
9. The method of claim 1 further selectively comprising an annealing step after the ion implantation to change the stress in the first and second high stress layers.