NEW METAMORPHIC HETEROJUNCTION BIPOLAR TRANSISTOR HAVING MATERIAL STRUCTURE FOR LOW COST FABRICATION ON LARGE SIZE GALLIUM ARSENIDE WAFERS

摘要

A metamorphic heterojunction bipolar transistor having a material structure for low cost fabrication on large size gallium arsenide wafers comprises a semi-insulating GaAs substrate; an undoped AlGaAsSb (or AlInGaAs) metamorphic buffer layer; a heavily doped n-type InGaAs layer , forming an ohmic contact for the collector of said MHBT; a lightly doped n-type InGaAs or InP or InAlAs layer, forming the collector of said MHBT; a heavily doped p-type InGaAs layer, forming the base and an ohmic contact for the base of said MHBT; an n-type InAlAs (or graded AlInGaAs or InP) layer, forming the emitter of said MHBT; and a heavily doped n-Such material structure makes high-indium content MHBTs feasible to be fabricated on large size gallium arsenide wafers with diameters of six inches or larger, resulting in lower manufacturing cost, higher power, higher efficiency at a very low operation voltage.