ION IMPLANT METHOD FOR FABRICATING MOS CAPACITOR TO EMBODY HIGHEST ION DENSITY ON SURFACE OF SILICON

摘要

A kind of purpose: ion implanting agent method, for manufacturing MOS (metal-oxide semiconductor (MOS)) capacitor, be arranged to embody a high ion density by forming a buffer oxide on the surface of silicon, be used to be readily formed a cell capacitor a shallow channel and by removal buffer oxide the ion concentration on the surface of silicon become due to the thickness of buffer oxide it is highest after. Construction: a STI (shallow trench isolation) (101) is formed in a silicon substrate (102) so that substrate to be divided into DRAM (dynamic random access memory) region, a DRAM beauty region and the logic region of a plane. One buffer oxide is formed in substrate, has STI. The photoresist of first predetermined shape is formed in buffer oxide to control the starting voltage of a cell transistor. By using the photoresist of the first predetermined shape as a mask, ion, for the starting voltage of adjustment unit transistor, the well that is implanted substrate to be formed in the presumptive area of substrate. The photoresist of second predetermined shape is formed in buffer oxide to control the starting voltage of a cell capacitor. By using the photoresist of the second predetermined shape as a mask, starting voltage of the ion for adjustment element capacitor is implanted to the interface for making highest ion concentration between the buffer oxide and surface of substrate.