发明名称 Photoresist masking in manufacture of semiconductor device
摘要 A semiconductor integrated circuit such as an MOS random access memory or RAM is made by standard N-channel silicon gate manufacturing methods but using positive photoresist for successive masking steps by re-exposure of the photoresist. In making ion implants for threshold adjustment, the positive photoresist is deposited and exposed using a first mask which defines the channel areas of transistors which are to have one threshold voltage; upon developing, the channel areas will be bare so a first implant will penetrate only these channel areas. Then, without stripping the photoresist, another exposure using a second mask defines the channel areas of transistors which are to have another threshold voltage. After the photoresist is developed a second time, another implant will penetrate the channel areas defined by the second mask as well as the first.
申请公布号 US4257826(A) 申请公布日期 1981.03.24
申请号 US19790083929 申请日期 1979.10.11
申请人 TEXAS INSTRUMENTS INCORPORATED 发明人 MATALONE, JR., SAMUEL
分类号 H01L29/78;G03F7/20;H01L21/027;H01L21/265;H01L21/336;H01L21/8242;(IPC1-7):H01L21/26 主分类号 H01L29/78
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