Charge-trapping memory device
View Patent ↗An oxidized region is arranged between a substrate of semiconductor material and a nitride liner, which covers wordline stacks of a memory cell array and intermediate areas of the substrate, and is provided to separate the nitride liner both from the substrate and from a memory layer sequence of dielectric materials that is provided for charge-trapping. The nitride liner is used as an etching stop layer in the formation of sidewall spacers used in a peripheral area to produce source/drain junctions of transistors of the addressing circuitry.
1. A method of making a semiconductor memory device, the method comprising:
forming a memory layer sequence over a semiconductor body, the memory layer sequence comprising a memory layer arranged between boundary layers;
forming a gate electrode over a portion of the memory layer sequence;
forming a sidewall insulator along a sidewall of the gate electrode;
forming an oxide region at the surface of the semiconductor body adjacent the sidewall insulator;
forming a nitride liner over the oxide region and the sidewall insulator; and
forming a dielectric material over the nitride liner.
2. The method of claim 1 , wherein forming a gate electrode comprises etching a gate electrode layer, the etching further comprising etching at least a portion of the memory layer sequence.
3. The method of claim 1 , further comprising doping source/drain regions in said semiconductor body after forming the gate electrode.
4. The method of claim 1 , wherein forming an oxide region comprises thermally oxidizing the semiconductor body.
5. The method of claim 1 , wherein forming an oxide region comprises performing an annealing procedure under a nitrogen atmosphere.
6. The method of claim 1 , wherein forming an oxide region comprises performing a radical-based oxidation process.
7. The method of claim 6 , wherein forming an oxide region further comprises forming an oxide layer over the sidewall insulators and over an upper surface of the gate electrode.
8. The method of claim 1 , further comprising forming an FET gate electrode at the same time as forming the gate electrode.
9. The method of claim 8 , further comprising forming FET sidewall insulators along sidewalls of the FET gate electrode.
10. The method of claim 8 , wherein the FET sidewall insulators are formed from portions of the dielectric material that was formed over the nitride layer.