Specific Process Knowledge/Thin film deposition/Deposition of Silicon Oxide/Deposition of Silicon Oxide using LPCVD TEOS: Difference between revisions
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==Deposition rate:== | ==Deposition rate and refractive index:== | ||
The deposition rate is normally a little below 10 nm/min | |||
The deposition rate is normally a little below 10 nm/min. But especially for short depositions, the deposition rate is higher and depends on the deposition time. The mean reason for this is that there is some TEOS (about 20-30) will be deposited during the pre- and post-deposition step, and this does not count as deposition time. The pre-deposition step is when the TEOS is introduced into the furnace tube before the deposition, and the pre-deposition step is when the TEOS gas line and mass flow controller are emptied through the furnace tube after the deposition. | |||
Before you use the furnace, it is recommended to look at process log to find the latest deposition rates. | |||
The refractive index is around 1.44. | |||
TEOS has compressive stress (around 100-300 MPa). | |||
==Using LPCVD TEOS as a masking material for KOH etching== | ==Using LPCVD TEOS as a masking material for KOH etching== | ||
It is possible to use TEOS as a masking layer in KOH etch however it is not as suitable as Silicon nitride for deep KOH etching. However for shallower etches it can be used. In comparison to silicon nitride TEOS has the advantage that it does not have the same pinhole problems. | It is possible to use TEOS as a masking layer in KOH etch however it is not as suitable as Silicon nitride for deep KOH etching. However for shallower etches it can be used. In comparison to silicon nitride TEOS has the advantage that it does not have the same pinhole problems. | ||