Method of making a cmos transistor using liquid phase deposition

Abstract

A method of making a complementary metal oxide semiconductor field effect transistor (CMOSFET) using liquid phase deposition. At first, a P-type silicon substrate is prepared, on which are formed a field oxide layer, a P-well, an N-well and a gate oxide layer. Next, a first polysilicon layer is formed. After doping the first polysilicon, a tungsten silicide layer is formed on the first polysilicon layer. Then, the first polysilicon layer and the tungsten silicide layer are patterned to form the polycide gate electrodes. With a mask shielding the area designated to be the N-channel FET, a P.sup.- type ion implant is performed. Then, a first silicon dioxide layer is formed by liquid phase deposition, followed by an anisotropic etching to form the first sidewall spacers. Then, a P.sup.+ type ion implant is performed. A second silicon dioxide layer is again formed by liquid phase deposition. Now, after removing the mask, an N.sup.- type ion implant is performed using the second silicon dioxide layer as a mask. Next, the second sidewall spacers are formed by depositing and etching back a layer of tetraethoxysilanes dielectric layer. Then, an N.sup.+ type ion implant is performed to form the N.sup.+ doped areas. After a boronphosphosilicate glass layer is deposited on the field oxide layer, the second silicon dioxide layer and the device area, the CMOSFET is completed.