Method of fabricating a non-volatile semiconductor memory
An non-volatile semiconductor memory having a linear arrangement of a plurality of memory cell transistors, includes: a first semiconductor layer having a first conductivity type; a second semiconductor layer provided on the first semiconductor layer to prevent diffusion of impurities from the first semiconductor layer to regions above the second semiconductor layer; and a third semiconductor layer provided on the second semiconductor layer, including a first source region having a second conductivity type, a first drain regions having the second conductivity type and a first channel region having the second conductivity type for each of the memory cell transistors.
1. A method for manufacturing a non-volatile semiconductor memory comprising:
forming a second semiconductor layer on a first semiconductor layer having a first conductivity type;
forming a third semiconductor layer having a second conductivity type on the second semiconductor layer;
forming a gate insulating film on the third semiconductor layer;
depositing a first conductive layer on the gate insulating film;
depositing an insulating film on the first conductive layer;
depositing a second conductive layer on the insulating film;
forming a groove penetrating the second conductive layer, the insulating layer and the first conductive layer so as to define a control gate electrode, an inter-electrode insulating film under the control gate electrode and a floating gate electrode under the inter-electrode insulating film; and
forming a memory cell transistor comprising a source region having the second conductivity type, a drain region having the second conductivity type and a channel region having the second conductivity type in the third semiconductor layer by ion implantation to the third semiconductor layer through the groove.
2. The method of claim 1 , further comprising:
forming the first semiconductor layer on a semiconductor substrate before forming the second semiconductor layer.