Method for forming and patterning a layer and/or substrate
In an embodiment, a method for forming features for semiconductor processing. A first mandrel and a second mandrel are formed on a substrate. A first spacer is formed along a first sidewall of the first mandrel, and a second spacer is formed along a second sidewall of the second mandrel. A gap is defined between the first spacer and the second spacer. The gap is filled by a gap-filling material. In some examples, the gap-filling material includes a doped silicon material. In some examples, the first spacer and the second spacer each include a doped silicon material.
1. A method for forming features for semiconductor processing, the method comprising:
forming a first mandrel and a second mandrel on a substrate;
forming a first spacer along a first sidewall of the first mandrel;
forming a second spacer along a second sidewall of the second mandrel, a gap being defined between the first spacer and the second spacer;
filling the gap by a gap-filling material, the gap-filling material comprising a doped silicon material different that a material of the first mandrel and the second mandrel, wherein the doped silicon material is boron-doped silicon with a boron concentration between 10 20 cm −3 and 10 24 cm −3 ; and
selectively removing the first spacer and the second spacer by an etch process, wherein the etch process does not etch the gap-filling material.
2. The method of claim 1 , wherein the first mandrel and the second mandrel are each carbon.
3. The method of claim 1 , wherein the etch process is a wet etch process.
4. The method of claim 3 , wherein the gap is seamlessly filled by the gap-filling material.
5. The method of claim 1 , wherein the boron concentration is at least 10 22 cm −3 .
6. The method of claim 1 , wherein the first spacer and the second spacer are each amorphous silicon.
7. The method of claim 6 , wherein the wet etch process comprises an etch solution comprising an alkali or alkaline etchant.
8. The method of claim 7 , wherein the alkali or alkaline etchant is at least one of KOH, NaOH, Ca(OH) 2 , and Ba(OH) 2 .
9. The method of claim 1 , wherein the first spacer and the second spacer are each silicon oxide deposited at low temperature.
10. The method of claim 9 , wherein the wet etch process comprises an etch solution having an acid etchant.
11. The method of claim 3 , wherein the doped silicon material is carbon-doped silicon.
12. The method of claim 11 , wherein the carbon-doped silicon is deposited by flowable CVD (FCVD).
13. The method of claim 11 , wherein the first spacer and the second spacer are each amorphous silicon.
14. The method of claim 13 , wherein the wet etch process comprises an etch solution having an alkali or alkaline etchant.
15. The method of claim 14 , wherein the alkali or alkaline etchant is at least one of KOH, NaOH, Ca(OH) 2 , and Ba(OH) 2 .
16. The method of claim 1 , wherein the boron-doped silicon is formed by a CVD process with a deposition temperature between about 150 degrees Celsius and about 200 degrees Celsius.
17. The method of claim 1 , wherein an etch solution of the wet etch process has a solution temperature in a range from about 10° C. to about 100° C.
18. The method of claim 17 , wherein the mandrels immersed in the etch solution for a time period in a range from about 10 seconds to about 100 seconds.
19. The method of claim 1 , wherein the first spacer and the second spacer are boron-doped silicon.