Abstract: A silicon layer formed atop a sapphire substrate is selectively recrystallized such that the original degraded quality of the crystallinity of an N-well region where a P-channel device is to be formed is enhanced, so that leakage in the P-channel device is reduced, while the high ultraviolet reflectance number of a P-well region where an N-channel device resides remains unaffected. The process according to the present invention involves implanting silicon into only that portion of the silicon layer where an N-conductivity well region for a P-channel device is to be formed. An N-conductivity type impurity is introduced into the silicon-implanted portion of the silicon layer, to form the N-conductivity well region. The structure is then annealed at a relatively low temperature for several minutes, which is sufficient to activate the phosphorus and to cause local recrystallization of the N-well region of the silicon layer, without essentially causing a redistribution of the phosphorus.

Abstract: A preamorphized silicon layer formed atop a sapphire substrate is selectively recrystallized such that the original degraded quality of the crystallinity of an N-well region where a P-channel device is to be formed is enhanced, so that leakage in the P-channel device is reduced, while the high UVR number of a P-well region where an N-channel device resides remains unaffected. The process according to the present invention involves implanting a recrystallization-inducing element, such as silicon, into only that portion of the preamorphized silicon layer where an N-conductivity well region for a P-channel device is to be formed. An N-conductivity type impurity is introduced into the silicon-implanted portion of the preamorphized silicon layer, to form the N-conductivity well region.