Fabricating semiconductor devices
    11.
    发明专利

    公开(公告)号:GB2296374A

    公开(公告)日:1996-06-26

    申请号:GB9425589

    申请日:1994-12-19

    Abstract: Disclosed is a method of fabricating an SOI substrate, comprising the steps of forming a first insulating layer on a single crystal silicon substrate; patterning the first insulating layer to form an opening; growing a single crystal silicon in the opening to form active and inactive regions; polishing the active region 31 as the first insulating layer as a polishing stopper to form a planarized surface; depositing a second insulating layer on the planarized surface; bonding a bonding substrate to the second insulating layer; and polishing the silicon substrate using the first insulating layer as a stopper up to a surface of the active region. By the method, a stray capacitance occurring between an SOI substrate and a metal wiring portion formed thereon can be significantly reduced owing to a relatively thick insulating layer therebetween, and a parasitic capacitance can be eliminated owing to an insulating layer interposed between a bonding substrate and an active region to be used as a buried collector.

    Bipolar transistor fabrication
    12.
    发明专利

    公开(公告)号:GB2296129A

    公开(公告)日:1996-06-19

    申请号:GB9425342

    申请日:1994-12-15

    Abstract: Fabrication of a bipolar transistor with a super self-aligned vertical structure of which the emitter 34, the base 32 and the collector 31 are vertically self-aligned, the fabrication method comprising the steps of forming a conductive buried collector region 22 in a silicon substrate 21 by using ion-implementation of an impurity and thermal-annealing; sequentially forming several layers 23 to 28; selectively removing the nitride and polysilicon layers 27, 28 to form a pattern; sequentially forming a silicon oxide layer 29, a nitride layer (17, Fig. 3a) and a silicon oxide layer (18) theron; forming a patterned photoresist layer thereon to define active and inactive regions and removing several layers on the active region to form an opening; forming a side wall (19, Fig. 3b) on both sides of the opening; forming a collector 31 on a surface portion of the buried collector region 22 up to a lower surface of the polysilicon layer 28; removing the side wall (19) and the third nitride layer (17) to expose a side surface of the second polysilicon layer 28; selectively forming a base 32 on an upper surface of the collector including a side surface of the polysilicon layer; forming side wall oxide layer 33 on both sides of the base and the silicon oxide to define an emitter region; forming an emitter 34 on the base 32 and forming electrodes 36 thereon. In the method, an active region is defined by a photolithography, and thereby a trench isolation acting as factors of lowering in integration and device-performance can be omitted in the method. As a result, fabrication sequence can be simplified and integration can be improved.

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