02-01-2020 дата публикации
Номер: US20200006151A1
Принадлежит:
A method includes forming a dummy gate stack over a semiconductor region of a wafer, and depositing a gate spacer layer using Atomic Layer Deposition (ALD) on a sidewall of the dummy gate stack. The depositing the gate spacer layer includes performing an ALD cycle to form a dielectric atomic layer. The ALD cycle includes introducing silylated methyl to the wafer, purging the silylated methyl, introducing ammonia to the wafer, and purging the ammonia. 1. A method comprising:forming a dummy gate stack over a semiconductor region of a wafer; and introducing silylated methyl to the wafer;', 'purging the silylated methyl;', 'introducing ammonia to the wafer; and', 'purging the ammonia., 'depositing a gate spacer layer using Atomic Layer Deposition (ALD) on a sidewall of the dummy gate stack, wherein the depositing the gate spacer layer comprises performing an ALD cycle to form a dielectric atomic layer, wherein the ALD cycle comprises2. The method of further comprising performing an anneal on the wafer after the gate spacer layer is formed claim 1 , wherein the anneal is performed with the wafer placed in an oxygen-containing gas.3. The method of claim 2 , wherein the anneal is performed at a temperature in a range between about 400° C. and about 500° C.4. The method of claim 2 , wherein before the anneal claim 2 , the gate spacer layer has a first nitrogen atomic percentage claim 2 , and after the anneal claim 2 , a portion of the gate spacer layer has a second nitrogen atomic percentage lower than the first nitrogen atomic percentage.5. The method of claim 2 , wherein before the anneal claim 2 , the gate spacer layer has a first k value higher than a k value of silicon oxide claim 2 , and after the anneal claim 2 , a portion of the gate spacer layer has a second k value lower than the k value of silicon oxide.6. The method of claim 1 , wherein the depositing the gate spacer layer further comprises introducing ammonia to the wafer before performing the ALD cycle.7. The ...
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