Soi process for forming a thin film transistor using solid phase epitaxy

Abstract

Of an amorphous Si film, a region to be formed into a lowly doped region such as the channel region of an MOS transistor is covered with a mask and an uncovered region is doped with an impurity. After this, the amorphous Si film is annealed and turned to signal crystal through solid phase epitaxial growth, and the mask itself is used as the electrode of a semiconductor device. By this impurity doping, a large-sized single-crystal Si film can be formed, and the impurity doping can be conducted in self-alignment with the electrode formation to produce a highly integrated semiconductor circuit.