Electrical Properties of Highly Crystallized Ge:H Thin Films Grown from VHF Inductively-Coupled Plasma of H_2-diluted GeH_4

摘要

Formation of highly crystallized Ge films on quartz substrate from VHF-ICP of GeH_4 and electrical properties of the films have been investigated. From the Hall measurements, we found that the films show p-type conduction and that carrier concentrations for the films of 92 and 98% in the crystallinity are 2.9 ×10~(19) and 5.7 ×10~(18)cm~(-3), respectively. In addition, we observed a carrier mobility of 22cm~2/Vs for the film with 98% crystallinity, which is ~2 times higher compared to 12cm~2/Vs of 92% case. This result suggests that defects in the films play a role on carrier type and transport properties.