Non-volatile memory device with improved erase speed
View Patent ↗A memory device may include a substrate, a first dielectric layer formed over the substrate and a charge storage element formed over the first dielectric layer. The memory device may also include a second dielectric layer formed over the charge storage element and a third dielectric layer formed over the second dielectric layer. The third dielectric layer may have a high dielectric constant and may be deposited at a relatively high temperature. A control gate may be formed over the third dielectric layer.
1. A method of manufacturing a semiconductor device, comprising:
forming a first dielectric layer over a substrate;
forming a dielectric charge storage element directly on the first dielectric layer;
forming a second dielectric layer directly on the dielectric charge storage element;
depositing aluminum oxide at a temperature greater than 325° C. and directly on the second dielectric layer, where depositing the aluminum oxide includes depositing an aluminum oxide layer having a thickness ranging from about 30 Å to about 200 Å; and
forming a control gate over the aluminum oxide.
2. The method of claim 1 , where the dielectric charge storage element comprises a nitride.
3. The method of claim 1 , where depositing the aluminum oxide at a temperature greater than 325° C. comprises:
depositing aluminum oxide at a temperature ranging from greater than 400° C. to about 500° C.
4. The method of claim 1 , where depositing the aluminum oxide comprises:
depositing the aluminum oxide using an atomic layer deposition process.
5. The method of claim 1 , where forming the dielectric charge storage element comprises:
forming a nitride layer having a thickness ranging from about 20 Å to about 100 Å.
6. The method of claim 5 , where forming the second dielectric layer comprises:
Forming a silicon oxide layer having a thickness ranging from about 15 Å to 100 Å.
7. The method of claim 1 , where depositing the aluminum oxide further includes depositing hafnium.
8. The method of claim 1 , further comprising:
forming a plurality of memory cells in the semiconductor device, where each of the memory cells stores charges representing two bits of information.