It can be seen that under these conditions a continuous homogeneous film with an almost

smooth surface and a roughness of no higher than 8–

10 Å was formed. In the films formed by other meth

ods, e.g., thermal oxygen deposition, the surface

roughness was 50–100 Å. It should be noted that in

SiO2

/Si(111), in contrast to metal silicides [9], no epi

taxial growth was observed and a polycrystalline struc

ture formed

Dear Dr. Manoj Yadav,

the roughness depend on the substrate (the type of silicon, predominant direction) and the vacuum inside the chamber. If there are good condition achieved you can get roughness less than 5 nm.

Best regards

So, you dont mean Thermal Evaporation,

Thermal Oxidation give more roughness than Thermal Evaporation.

It can use heat treatment for various time after preparing the films. This will give fine surface.

Best regard

yes, but you must use the heat treatment after preparing the films to get more smooth surface.

Dear Manoj,

In case of thermal oxidation using dry O2 or vapor oxidation rate depends on substrate temperature and the supply rate of the oxidizing species to the interface between the Si and SiO2. So, to achieve as homogeneous silicon layer one has to keep these two parameters constant through out the surface of the wafer.

So the fluctuations in the thickness of the oxide depends on controlling the homogeneity of these two parameters.

Best wishes