Scalable interpoly dielectric stacks with improved immunity to program saturation
View Patent ↗A method for manufacturing a non-volatile memory device is described. The method comprises growing a layer in a siliconoxide consuming material, e.g. DyScO, on top of the upper layer of the layer where charge is stored. A non-volatile memory device is also described. In the non-volatile memory device, the interpoly/blocking dielectric comprises a layer in a siliconoxide consuming material, e.g. DyScO, on top of the upper layer of the layer where charge is stored, the siliconoxide consuming material having consumed at least part of the upper layer.
1. A method for manufacturing a non-volatile memory device, comprising:
providing a substrate comprising a channel between two doped regions;
applying a first dielectric on top of said channel, said first dielectric having predetermined properties for functioning as a tunnel dielectric;
applying a charge storage layer on top of said tunnel dielectric, said charge storage layer having predetermined properties for enabling storage of charge in said layer and comprising an upper layer containing silicon dioxide;
applying a second dielectric, comprising a layer in a siliconoxide consuming material, on top of the upper layer of the charge storage layer on top of said charge storage layer, said second dielectric having predetermined properties for minimizing charge currents through the second dielectric;
applying a control gate on top of said second dielectric; and
subjecting the device to a post deposition thermal treatment in which a predetermined thermal budget is applied, such that said siliconoxide consuming material consumes at least part of the upper layer of the charge storage layer.
2. The method according to claim 1 , wherein the layer of siliconoxide consuming material forms substantially the whole of the second dielectric.
3. The method according to claim 1 , wherein applying a second dielectric further comprises growing a layer of low-k material on top of the layer of siliconoxide consuming material.
4. The method according to claim 3 , wherein applying the second dielectric further comprises growing another layer in the siliconoxide consuming material on top of the layer of low-k material.
5. The method according to claim 1 , wherein the control gate which is applied on top of the second dielectric is a high-workfunction metal gate.
6. The method according to claim 1 , wherein the siliconoxide consuming material comprises a rare earth material.
7. The method according to claim 6 , wherein the siliconoxide consuming material is dysprosium scandate, DyScO.
8. The method according to claim 1 , wherein applying said predetermined thermal budget comprises subjecting the device to a temperature between 800° C. and 1000° C. for a given time period.