Title :
A possible near-ballistic collection in an AlGaAs/GaAs HBT with a modified collector structure
Author :
Ishibashi, Tadao ; Yamauchi, Yoshiki
Author_Institution :
Electr. Commun. Labs., NTT, Kanagawa, Japan
fDate :
4/1/1988 12:00:00 AM
Abstract :
An AlGaAs/GaAs heterojunction bipolar transistor (HBT) structure with an n-p+1-i-p+2-n+ doping profile that enables electron collection in the Γ-valley of GaAs is presented. In fabricated HBTs operating at low collector current density, fT reaches its peak value when the potential variation in the i collector layer is around 0.4 V, which indicates that the electron transport is dominated by the Γ-valley feature in GaAs. A high fT value of 105 GHz obtained at a collector current density of 5×104 A/cm2 also demonstrates the significance of the proposed near-ballistic collection structure
Keywords :
III-V semiconductors; aluminium compounds; bipolar transistors; gallium arsenide; high field effects; semiconductor junctions; Γ-valley; 105 GHz; AlGaAs-GaAs; HBT; collector current density; electron collection; electron transport; heterojunction bipolar transistor; low collector current density; modified collector structure; n-p+1-i-p+2-n+ doping profile; near-ballistic collection structure; Acceleration; Ballistic transport; Current density; Cutoff frequency; Doping profiles; Electrons; FETs; Gallium arsenide; Heterojunction bipolar transistors; Voltage;
Journal_Title :
Electron Devices, IEEE Transactions on
