Split-Gate Flash Memory Cell Odd/Even Fail Pattern Failure Analysis

Abstract A NOR-type split gate embedded Flash memory product program marginal fail with odd/even word line failure pattern. Based on cell current comparison, programming cycling tests and voltage drop measurements, the invisible cause of even/odd cells weak program failure mechanism was verified and confirmed visibly by cross sectioning and junction stain treatment. This problem was then solved by tightening photo alignment control and exposure conditions.