| 摘要 |
PURPOSE:To obtain a bipolar transistor with low threshold voltage by using a single crystal having a narrow band with gap Eg, a mixed crystal, a superlattice or an impurity adding layer as a base layer. CONSTITUTION:N-Ga1-xInxSb, P-Ga1-xInxSb and N-Al1-yInySb are each laminated onto a semi-insulating InSb substrate while interposing inclined layers. With a mixed crystal, lattice constants and Eg are approximately in direct proportion to mixed ratios (x), (y), and change into a linear shape when (x) and (y) are varied to 1 from 0, the lattice constants coincide on x=y, and a crystal defect is not generated on the hetero-interface between an emitter and a base. A layer 1-6 consists of Ga(1-y)(1-Z)Al(1-x)(1-z)In(1-z)+xySb, a lattice constant is kept constant when (z) is altered continuously to 1 on the emitter side and to 0 on the base side, Ege continuously changes to Egb, and no spike is generated. A layer 1-2 is composed of an alternate depositing layer of InSb and Ga1-yInySb, and (y) is brought close to (y) of a collector layer by stages from 1 and a transition by a lattice mismatch is absorbed on a stepped interface. According to the constitution, the Egb of a bipolar element at Ege>=Egb is narrowed, and rise threshold voltage can be lowered. |
