A Long-Wavelength Optical Receiver Using a Short-Channel Si-MOSFET

Copyright© 1983 American Telephone and Telegraph Company. Printed in U.S.A. A Long-Wavelength Optical Receiver Using a Short-Channel Si-MOSFET By K. O G A W A , B. OWEN, and H. J. BOLL (Manuscript received April 21,1982) Recent improvements in fine-line technology have resulted in silicon metal oxide semiconductor field-effect transistors (MOSFETs) with channel lengths between 0.2 and 0.8 fim. We have measured the low-frequency noise in these transistors and find it to be smaller than that in comparable GaAs-metal Schottky valve field-effect transistors (MESFETs). Theoretical considerations on the FET noise and experimental results at 45 Mb/s indicate that Si-MOSFETs can compete with GaAs-MESFETs in hybrid photoamplifier circuits. As a natural extension, Si-MOSFETs can also be used for the complete monolithic integration of the receiver circuit with the benefits of reliability and improved performance. I. INTRODUCTION In the absence of high-performance avalanche photodiodes for longwavelength optical receivers, p-i-n photodiodes with low-noise amplifiers have been used. 1 The amplifiers are designed with ultra-low-noise components to realize high receiver sensitivities. Up until now, GaAsmetal Schottky valve field-effect transistors (MESFETs) were used exclusively as low-noise components at bit rates less than 300 Mb/s. 2,3 We have fabricated a short-channel Si-metal oxide semiconductor field-effect transistor (MOSFET) 4 and used this M O S F E T in a hybrid integrated receiver circuit at 45 Mb/s.