11.
    发明专利
    未知

    公开(公告)号:DE3751732D1

    公开(公告)日:1996-04-18

    申请号:DE3751732

    申请日:1987-03-24

    Applicant: IBM

    Abstract: Disclosed is a process of growing a conformal and etch-resistant silicon dioxide on a surface by forming a conformal layer of polysilicon and subjecting the polysilicon to thermal oxidation to completely convert the polysilicon into (poly) silicon oxide. Disclosed also is a method of forming an isolation trench in a semiconductor substrate having a high integrity oxide sidewall. After forming the trench (58) in the substrate surface using a suitable etch mask and RIE, a single (thermal) oxide or dual (thermal) oxide and (CVD) nitride liner (64) is formed on all trench surfaces. A conformal layer of undoped polysilicon (66) is then formed (by. e.g. LPCVD) on the liner. By subjecting to thermal oxidation, the polysilicon is completely converted into a conformal (poly) silicon oxide layer (68) having a thickness about 2.5 times that of the polysilicon layer. The resulting (poly) silicon oxide has the conformality of CVD oxide and the high etch resistance of thermally grown oxide. Alternatively, prior to forming the (poly) silicon oxide, the polysilicon layer is removed from the trench floor and the substrate surface in order to limit volume expansion of the polysilicon to a single direction perpendicular to the trench walls. The trench is filled with oxide, epitaxial silicon, polysilicon, polymers or metal, as desired. For achieving substrate contact through the trench, the trench bottom is opened up by RIE. Polysilicon is deposited with in-situ doping at a high temperature to fill the trench and simultaneously diffuse the dopant from the polysilicon fill into the underlying substrate to form a channel stop.

    12.
    发明专利
    未知

    公开(公告)号:BR8702320A

    公开(公告)日:1988-02-17

    申请号:BR8702320

    申请日:1987-05-06

    Applicant: IBM

    Abstract: Disclosed is a process of growing a conformal and etch-resistant silicon dioxide on a surface by forming a conformal layer of polysilicon and subjecting the polysilicon to thermal oxidation to completely convert the polysilicon into (poly) silicon oxide. Disclosed also is a method of forming an isolation trench in a semiconductor substrate having a high integrity oxide sidewall. After forming the trench (58) in the substrate surface using a suitable etch mask and RIE, a single (thermal) oxide or dual (thermal) oxide and (CVD) nitride liner (64) is formed on all trench surfaces. A conformal layer of undoped polysilicon (66) is then formed (by. e.g. LPCVD) on the liner. By subjecting to thermal oxidation, the polysilicon is completely converted into a conformal (poly) silicon oxide layer (68) having a thickness about 2.5 times that of the polysilicon layer. The resulting (poly) silicon oxide has the conformality of CVD oxide and the high etch resistance of thermally grown oxide. Alternatively, prior to forming the (poly) silicon oxide, the polysilicon layer is removed from the trench floor and the substrate surface in order to limit volume expansion of the polysilicon to a single direction perpendicular to the trench walls. The trench is filled with oxide, epitaxial silicon, polysilicon, polymers or metal, as desired. For achieving substrate contact through the trench, the trench bottom is opened up by RIE. Polysilicon is deposited with in-situ doping at a high temperature to fill the trench and simultaneously diffuse the dopant from the polysilicon fill into the underlying substrate to form a channel stop.

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