Method for programming a semiconductor memory device

Claim 1

A method of programming a floating gate transistor, said transistor comprising a semiconductor substrate including a source region, a drain region and a channel extending between said source and drain regions, a floating gate extending over a portion of said channel and ending over said channel, said floating gate integrally including first and second floating gate portions, said first floating gate portion extending proximately to said channel with a thin oxide layer therebetween and said second floating gate portion extending away from said channel, a program gate capacitively coupled through a dielectric oxide layer to said second floating gate portion, and a control gate laterally remote from said program gate and extending through a dielectric oxide layer over said first floating gate portion from above said source region to above said drain region, said program gate and said control gate having lateral edges facing each other in a spaced apart relationship, said method comprising the steps of: applying a high voltage to said program gate thereby capacitively coupling a high voltage to said second floating gate portion; applying a low voltage to said control gate; and applying a voltage not greater than 5 V to said drain region, to thereby cause a very high hot-electron injection towards said floating gate while achieving, within a microsecond, a programming of said transistor without the need for an external voltage supply.

Claim 2

A method of programming a floating gate transistor, said transistor comprising a semiconductor substrate including a source region, a drain region and a channel extending between said source and drain regions, a floating gate extending over a portion of said channel and ending over said channel, said floating gate integrally including first and second floating gate portions, said first floating gate portion extending proximately to said channel with a thin oxide layer therebetween and said second floating gate portion extending away from said channel, a program gate capacitively coupled through a dielectric oxide layer to said second floating gate portion, and a control gate laterally remote from said program gate and extending through a dielectric oxide layer over said first floating gate portion from above said source region to above said drain region, said program gate and said control gate having lateral edges facing each other in a spaced apart relationship, said method comprising the steps of: applying a high voltage to said program gate thereby capacitively coupling a high voltage to said second floating gate portion; applying a low voltage to said control gate; and applying a voltage not greater than 5 V to said drain region, to thereby cause a very high hot-electron injection towards said floating gate while achieving, within a microsecond, a programming of said transistor without the need for an external voltage supply.