METHOD OF FORMING CONTIGUOUS SELF-ALIGNED IMPLANTED SEMICONDUCTOR REGIONS AND METHOD OF FORMING AN INTEGRATED CMOS STRUCTURE

摘要

Contiguous self-aligned ion implanted regions (48, 60; 102, 106) are formed in a semiconductor wafer (40; 90) by the steps of (a) implanting ions through an opening (46; 100) in a first mask (44; 98) formed on the wafer to produce a first ion implanted region (48; 102), (b) depositing a barrier layer (50; 104) through the opening (46; 100) in the first mask, (c) forming a second mask (56; 105) over the wafer and over the barrier layer, the second mask having a window (58; 107) which exposes an edge portion of the barrier layer, the alignment of the window being non-critical; and (d) implanting ions through the window (58; 107) in the second mask to produce a second ion implanted region (60; 106) in the wafer, the second ion implanted region having an edge determined by the exposed edge of the barrier layer.
An application of the method set out above is in the production of integrated CMOS structures. Thus active devices can be formed in the first ion implanted region and the second ion implanted region can serve as a field isolation region.