Nonvolatile split gate memory cell having oxide growth

摘要

A split gate nonvolatile memory cell on a semiconductor layer is made by forming a gate dielectric over the semiconductor layer. A first layer of gate material is deposited over the gate dielectric. The first layer of gate material is etched to remove a portion of the first layer of gate material over a first portion of the semiconductor layer and to leave a select gate portion having a sidewall adjacent to the first portion. A treatment is applied over the semiconductor layer to reduce a relative oxide growth rate of the sidewall to the first portion. Oxide is grown on the sidewall to form a first oxide on the sidewall and on the first portion to form a second oxide on the first portion after the applying the treatment. A charge storage layer is formed over the first oxide and along the second oxide. A control gate is formed over the second oxide and adjacent to the sidewall.