Semiconductor resistor with uniforms current distribution at its contact surface
    1.
    发明授权
    Semiconductor resistor with uniforms current distribution at its contact surface 失效
    具有均匀电流分布的半导体电阻在其接触表面

    公开(公告)号:US3629667A

    公开(公告)日:1971-12-21

    申请号:US3629667D

    申请日:1969-03-14

    Applicant: IBM

    CPC classification number: H01L29/8605

    Abstract: A diffused resistor for semiconductor integrated circuits which avoids the problems caused by the high surface current density. The resistor includes at least one semiconductor region of conductivity type opposite to the resistor proper located between a pair of ohmic contacts to the resistor region. This semiconductor region diverts the current flow from the surface of the resistor region and causes a more uniform current distribution across the surface of the ohmic contacts.

    Process for forming semiconductor devices with polycrystalline diffusion pathways and devices formed thereby
    3.
    发明授权
    Process for forming semiconductor devices with polycrystalline diffusion pathways and devices formed thereby 失效
    用多晶硅扩散路径形成半导体器件的方法及其形成的器件

    公开(公告)号:US3621346A

    公开(公告)日:1971-11-16

    申请号:US3621346D

    申请日:1970-01-28

    Applicant: IBM

    Abstract: A process wherein epitaxial silicon is grown on a substrate of single-crystal silicon with islands of silicon dioxide thereon, whereby single crystal epitaxial material is grown over the single-crystal substrate areas, but polycrystalline silicon is grown over the silicon dioxide islands. Since impurity diffusion occurs more rapidly through polycrystalline material than through single-crystalline material diffusion schemes can be obtained using the rapid diffusion pathway provided by the polycrystalline material to provide subsurface configurations which are completely enclosed by single-crystal material, for instance, a buried subcollector can be formed by growing polycrystalline silicon material horizontally, extending a narrow polycrystalline channel upward to the device surface, and subsequently diffusing impurities down through the narrow vertical polycrystalline channel into the lateral polycrystalline subcollector. Further, an electrical underpass can be formed which has a very low resistance by again using the rapid diffusion characteristics of polycrystalline silicon to grow polycrystalline silicon of the desired shape which can be rapidly diffused to provide, in comparison to background, a high conductivity path. By control of the substrate crystalline orientation, polycrystalline material can be grown which terminates because of sidewall convergence. This is desirable where it is required to terminate polycrystalline growth and begin single-crystal growth without any alteration in process conditions. The devices described are also claimed.

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