Fabrication and characterization of in situ-doped a-Si0.8C0.2 emitter bipolar transistors

Silicon cal bon emitters were deposited by plasma enhanced chemical vapour deposition (PECVD) on a conventional silicon transistor base. The resulting transistors were annealed after the emitter had been deposited which led t o the dopant diffusing from the amorphous layer into the crystalline base. This paper analyses the effect of the annealing temperature on the properti es of the amorphous layer and on the electrical characteristics of the tran sistors. First, after isochronal annealing between 740 degrees C and 880 de grees C, the physical properties of PECVD a-Si0.8C0.2:H(n) layers were meas ured. Then, the base current of the transistors was analysed as a function of the: annealing temperature to gain deeper insight into its physical orig in. (C) 2000 Elsevier Science Ltd. All rights reserved.