Patent attributes
A method for forming gate dielectric layers having different thicknesses is provided, The method includes forming a lower oxide layer, a nitride layer, and an upper oxide layer on a semiconductor substrate; performing a first deglaze process to the semiconductor substrate keeping the lower oxide layer, the nitride layer, and the upper oxide layer in a first region, while removing the nitride layer and the upper oxide layer in second, third, and fourth regions; forming the first gate dielectric layer having a first thickness in the second, third, and fourth regions; performing a second deglaze process to the first gate dielectric layer in the third region, thereby forming a second gate dielectric layer having a second thickness; and performing a third deglaze process on the first gate dielectric layer on the fourth region, thereby forming a third gate dielectric layer having a third thickness.
