Implant after through-silicon via (TSV) etch to getter mobile ions
A method of making a semiconductor device includes disposing a mask on a substrate; etching the mask to form an opening in the mask; etching a trench in the substrate beneath the opening in the mask; and implanting a dopant in an area of the substrate beneath the opening of the mask, the dopant capable of gettering mobile ions that can contaminate the substrate; wherein the dopant extends through the substrate from a sidewall of the trench and an endwall of the trench.
1. A method of making a semiconductor device, the method comprising:
disposing a mask on a substrate;
etching the mask to form an opening in the mask;
etching a trench in the substrate beneath the opening in the mask;
implanting a dopant, by an implantation technique, in an area of the substrate beneath the opening of the mask such that the dopant extends within the substrate from a substantially vertical sidewall of the trench and substantially horizontal bottom endwall of the trench, the dopant capable of gettering mobile ions that can contaminate the substrate; and
simultaneous with implanting the dopant, implanting a source/drain region of an nFET device adjacent the trench with an element selected from the group consisting of arsenic and phosphorous.
2. The method of claim 1 , further comprising filling the trench with a conductive material to form a through-silicon via (TSV).
3. The method of claim 1 , wherein the dopant comprises arsenic, phosphorus, or a combination thereof.
4. The method of claim 1 , wherein the substrate comprises a base semiconductor substrate, a buried dielectric layer disposed on the base semiconductor substrate, and a silicon layer disposed on the buried dielectric layer.
5. The method of claim 4 , wherein the trench extends about 3 to about 500 microns through the base semiconductor substrate.
6. The method of claim 1 , wherein the dopant getters ions by segregating the ions away from active device areas.
7. The method of claim 1 , wherein the dopant extends through the substrate about 0.25 to about 0.5 microns from the sidewall of the trench.
8. The method of claim 1 , wherein the dopant extends through the substrate about 0.25 to about 0.5 microns from the endwall of the trench.
9. A method of making a semiconductor device, the method comprising:
disposing a mask on a substrate;
etching the mask to form an opening in the mask;
etching a trench in the substrate beneath the opening in the mask;
performing a first implantation technique, after etching the trench, to introduce a dopant in a first area of the substrate beneath the opening of the mask, the dopant capable of gettering mobile ions that can contaminate the substrate;
during the first implantation technique, implanting a source/drain region of an nFET device adjacent the trench with an element selected from the group consisting of arsenic and phosphorous;
performing a second implantation technique, after performing the first implantation technique, to introduce a dopant in a second area of the substrate beneath the opening of the mask, a portion of the second area being different than the first area, and the dopant capable of gettering mobile ions that can contaminate the substrate;
wherein the dopant extends within the substrate from a substantially vertical sidewall of the trench and a substantially horizontal bottom endwall of the trench.
10. The method of claim 9 , wherein the ions are sodium ions or potassium ions.
11. The method of claim 9 , wherein the ions are copper ions.
12. The method of claim 9 , wherein the dopant getters ions by segregating the ions away from active device areas.
13. The method of claim 9 , wherein performing the second implantation technique comprises rotating the substrate to position the substrate at an oblique angle with respect to a normal axis of the substrate during the first implantation technique.
14. The method of claim 13 , further comprising rotating the substrate to position the substrate at another oblique angle and performing a third implantation technique to introduce the dopant in a third area of the substrate, the third area being different than the first or second areas.