Ion Implanted p-n Junctions in GaAs_0.6P_0.4

Abstract

p-n junctions have been fabricated in n-type GaAs_0.6P_0.4 by implanting zinc ions, at room temperature. The effect of annealing schedule upon the electrical characteristics of the implanted layers has been examined. When annealed below 550° C, the layer is p-type and has a high resistivity. If the layer is annealed between 550° C and 650° C, the layer has very high resistivity and shows no indications of p-type conduction and this is thought to be due to compensation of the electrically active zinc atoms by damage. On annealing at 700° C and above, the layer reverts to p-type conductivity and the sheet resistance falls rapidly with increasing anneal temperature. The optimum anneal temperature is found to be 800° C but not all the zinc atoms are electrically active.

Diodes have been fabricated for electron emission studies and their properties are compared with diffused diodes. Stable electron emission currents of 10^-7 amps have been obtained for forward bias currents of 20 mA.