Type conversion in close contact rapid thermal annealing of Si-implanted InP

A number of methods have been studied to prevent the preferential loss of P from the InP surface which occurs at the annealing temperatures necessary to produce good implant activation. These include the use of an encapsulant (typically a dielectric), a controlled atmosphere which presents an overpressure of P, and close contact of a ''dummy'' InP sample in proximity to the implanted InP sample. However, it has been established that dielectric deposition, even at low temperatures (--300/sup 0/C), allows the loss of measurable amounts of P (4), although the formation of a rho-type layer has not been observed for Si-implanted samples annealed with an appropriate dielectric encapsulant. Because of the measurable loss of P which occurs during deposition, alternatives to encapsulation have ben studied. Close contact annealing is very attractive due to its simplicity, but as this article addresses, this method is clearly inadequate for annealing high dose Si implants in InP.