BORON AND PHOSPHORUS DOPING OF A-SIC-H THIN-FILMS BY MEANS OF ION-IMPLANTATION

A detailed study of the structural and optoelectronic properties of bo ron- and phosphorus-implanted a-SiC:H thin films is presented. The fil ms have been deposited by ultra high vacuum plasma-enhanced chemical v apour deposition and have energy gap values of about 2 eV. The effects of varying carbon content, boron-and phosphorus-implanted dose and an nealing temperatures are reported. It is found that ion implantation s trongly modifies the structure, producing an increase of monohydride b onds. After annealing the defect density is mainly affected by dopant type and concentration rather than by residual radiation damage. We al so show that no enhanced gap shrinkage is produced by boron with respe ct to phosphorus doping if the film composition is the same. A compari son with gas phase doping is also reported.