Methods of forming an array of flash field effect transistors and circuitry peripheral to such array

摘要

A method of forming an array of FLASH field effect transistors and circuitry peripheral to such array includes forming a sacrificial oxide over an array area and a periphery area of a semiconductor substrate. After forming the sacrificial oxide, at least one conductivity modifying implant is conducted into semiconductive material of the substrate within the array without conducting the one conductivity modifying implant into semiconductive material of the substrate within the periphery. The sacrificial oxide is removed from the array while the sacrificial oxide is left over the periphery. After removing the sacrificial oxide from the array, at least some FLASH transistor gates are formed within the array and at least some non-FLASH transistor gates are formed within the periphery