High frequency bipolar transistor with integral thermally compensated degenerative feedback resistance

    公开(公告)号:US3868720A

    公开(公告)日:1975-02-25

    申请号:US42566873

    申请日:1973-12-17

    CPC classification number: H01L29/7304 H01L29/00

    Abstract: A high frequency bipolar transistor is provided with integral thermally compensated degenerative feedback resistance. The emitter, base and collector regions of the transistor are positioned in an epitaxial layer of a semiconductor body adjoining a major surface with an adjoining substrate portion having an impurity concentration greater than about 1 X 1018 carriers/cm3. The emitter region adjoins the major surface in at least one strip configuration preferably of width less than about 10 microns, and has an impurity concentration at the major surface of at least about 1 X 1018 carriers/cm3. The collector region adjoins the substrate portion and the major surface spaced from the emitter region has a thickness of less than about 10 microns at the active portions, and has an impurity concentration therethrough of less than about 1 X 1014 carriers/cm3. The base region has a thickness of less than 2 microns and an impurity concentration between about 5 X 1014 and 5 X 1017 carriers/cm3 between the emitter and collector regions in the epitaxial layer and adjoins the major surface at least peripherally of the emitter region. First, second and third metal contacts spaced substantially parallel of strip configurations make separate ohmic contact to the emitter base and collector regions, respectively. A dielectric layer is applied on the major surface at least adjacent the first metal contact, with a conductor layer of strip configuration on the dielectric layer spaced from and extending substantially parallel to the first metal contact. And a degenerative resistor layer on the first contact, the dielectric layer and the conductor layer extends substantially the length of the first metal contact and the conductor layer and makes ohmic contact to both the first metal contact and the conductor layer along the length thereof, while remaining substantially insulated from the second and third metal contacts and the base and collector regions.

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