Charge carrier response time in sputtered a-C/n-Si heterojunctions

Amorphous carbon (a-C)/n-Si heterojunctions were developed by rf magnetron sputtering from a carbon target on Si(100) n-type substrates kept at room t emperature. Subsequent metallization by the deposition of sputtered TiN on top of the carbon films resulted in the creation of effective heterojunctio n devices as shown by electrical characterization. The electrical performan ce of the devices was further investigated by admittance spectroscopy, allo wing the calculation of the charge carrier response time which was found to be of the order of 10(-6) s at room temperature, the lower value reported so far when compared to similar values reported for chemically vapor deposi ted films. These results showed that the devices were suitable for use in f ast electronics working in hard environments. (C) 2001 American Institute o f Physics.