Title :
A high-gain GaAs/AlGaAs n-p-n heterojunction bipolar transistor on
Author :
Won, T. ; Litton, C.W. ; Morkoc, Hadis ; Yariv, Amnon
Author_Institution :
Coordinated Sci. Lab., Illinois Univ., Urbana, IL, USA
Abstract :
High-gain GaAs/AlGaAs n-p-n heterojunction bipolar transistors (HBT´s) on Si substrates grown by molecular beam epitaxy (MBE) have been fabricated and tested. In this structure, an n/sup +/-InAs emitter cap layer was grown in order to achieve a nonalloyed ohmic contact. Typical devices with an emitter dimension of 50*50 mu m/sup 2/ exhibited a current gain as high as 45 at a collector current density of 2*10/sup 3/ A/cm/sup 2/ with an ideality factor of 1.4. This is the highest current gain reported for HBT´s grown on Si substrates. Breakdown voltages as high as 10 and 15 V were observed for the emitter-base and collector-base junctions respectively. The investigation on devices with varying emitter dimensions demonstrates that much higher current gains can be expected.<>
Keywords :
III-V semiconductors; aluminium compounds; bipolar transistors; gallium arsenide; molecular beam epitaxial growth; p-n heterojunctions; semiconductor epitaxial layers; 10 V; 15 V; GaAs-AlGaAs; HBT´s; Si substrates; breakdown voltages; collector current density; collector-base junctions; current gain; emitter cap layer; emitter dimensions; emitter-base junctions; ideality factor; molecular beam epitaxy; n-p-n heterojunction bipolar transistor; nonalloyed ohmic contact; Bipolar transistors; Digital integrated circuits; Etching; Gallium arsenide; Gold; Heterojunction bipolar transistors; Laboratories; Molecular beam epitaxial growth; Substrates; Testing;
Journal_Title :
Electron Device Letters, IEEE
