发明名称 |
DOUBLE LAYER PHOTORESIST PROCESS FOR WELL SELF-ALIGN AND ION IMPLANTATION MASKING |
摘要 |
<p>A technique is disclosed for obtaining a self-aligned twin-well structure in a CMOS process. A double layer of two different photoresist materials is employed to obtain an overhang photoresist structure used for the p-well masking and ion implantation process. After the p-well implantation, pure aluminum is deposited over the wafer, forming a first layer over the p-well region and a second layer over the photoresist layers. A metal lift-off procedure is performed to dissolve the photoresist layers and thereby remove the second layer of metal. The first layer of aluminum remaining on the wafer forms a conjugate of the p-well pattern and serves as the n-well mask for ion implantation. The invention provides a straightforward method for achieving the self-aligned twin-well structure in CMOS processes, and is adapted to high energy ion implantation for achieving retrograde impurity profiles.</p> |
申请公布号 |
EP0256030(B1) |
申请公布日期 |
1990.10.24 |
申请号 |
EP19870900395 |
申请日期 |
1986.11.24 |
申请人 |
HUGHES AIRCRAFT COMPANY |
发明人 |
LIAO, KUAN, Y.;LEE, WILLIAM, W., Y. |
分类号 |
H01L21/265;H01L21/027;H01L21/266;H01L21/8238;H01L27/092 |
主分类号 |
H01L21/265 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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