STATIC DOMAIN IN DEVICE WITH INTERVALLEY ELECTRON TRANSFER ON THE BASIS OF VARIBAND AlGaAs

Abstract

The use of variband semiconductors in uniformly doped devices with the effect of intervalley electron transfer can lead to the appearance of a static electric domain. The interest in the static domain is due to the possibility of creating a local electric field sufficient for impact ionization of zone area. Diodes with avalanche ionization in the static domain can be used as active elements of noise generators. The article analyzes the process of formation of a static domain and avalanche multiplication of current in it on the basis of the two-temperature model variband AlGaAs. It is shown that for the formation of a static domain at room temperature, it is necessary that the minimum value of the energy gap between the G-valley and the closest by energy side valley was smaller than the thermal energy of the electrons at the rate of change of the energy gap to coordinate more than 150 eV×cm–1. Accordingly, in devices based on Al0.36Ga0.64As–GaAs cathode static domain is formed, and on the basis of GaAs–Al0.36Ga0.64As anode static domain is formed. The variband semiconductor compounds in which it is possible to form a static domain were determined. Using variband compounds Al0.36Ga0.64As–GaAs with low levels of doping in the vicinity of the cathode increases the effective and integral current multipliers as compared to GaAs-diode. The findings expand the knowledge of the physical processes of charge transport in complex semiconductor structures. They can be used for technological development of new high-speed devices, such as transistors, Gunn diodes, diodes with a stationary domain, avalanche-transit diodes, frequency multipliers.

Keywords

• current multiplication factor
• graded-gap semiconductor
• gunn diode
• impact ionization
• intervalley electron transfer
• noise generator
• static domain