Method of forming a polysilicon sidewall oxide region in a memory cell
First Claim
1. A method of fabricating a memory cell of a semiconductor device, the method comprising:
- depositing a conductive layer having a top surface and a side surface;
forming a partial ONO layer over the top surface of the conductive layer by depositing a first oxide layer on the top surface of the conductive layer and a silicon nitride layer on top of the first oxide layer, wherein the side surface of the conductive layer remains exposed; and
forming a sidewall oxide layer adjacent the side surface of the conductive layer by a process including;
depositing a high temperature oxide (HTO) film directly on the side surface of the conductive layer and on top of the silicon nitride layer thereby forming the ONO layer; and
performing a rapid thermal oxidation (RTO) anneal.
13 Assignments
0 Petitions
Accused Products
Abstract
Methods of fabricating a memory cell of a semiconductor device, e.g., an EEPROM cell, having a sidewall oxide are disclosed. A memory cell structure may be formed including a floating gate and an ONO film over the conductive layer. A sidewall oxide may be formed on a side surface of the floating gate by a process including depositing a thin high temperature oxide (HTO) film on the side surface of the conductive layer, and performing a rapid thermal oxidation (RTO) anneal. The thin HTO film may be deposited before or after performing the RTO anneal. The sidewall oxide formation process may provide an improved memory cell as compared with known prior art techniques, e.g., in terms of endurance and data retention.
-
Citations
19 Claims
-
1. A method of fabricating a memory cell of a semiconductor device, the method comprising:
-
depositing a conductive layer having a top surface and a side surface; forming a partial ONO layer over the top surface of the conductive layer by depositing a first oxide layer on the top surface of the conductive layer and a silicon nitride layer on top of the first oxide layer, wherein the side surface of the conductive layer remains exposed; and forming a sidewall oxide layer adjacent the side surface of the conductive layer by a process including; depositing a high temperature oxide (HTO) film directly on the side surface of the conductive layer and on top of the silicon nitride layer thereby forming the ONO layer; and performing a rapid thermal oxidation (RTO) anneal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. A method of fabricating a memory cell of a semiconductor device, the method comprising:
-
forming a stack structure on a wafer by; depositing a conductive layer on a first oxide layer; forming a second oxide layer over a top surface of the conductive layer, forming a silicon nitride layer over the top surface of the first oxide layer, and forming and patterning a protective photoresist layer silicon nitride layer and performing an etching down to the first oxide layer, wherein a side surface of the conductive layer remains exposed; depositing a high temperature oxide (HTO) film immediately on the side surface of the conductive layer and on top of the silicon nitride layer; and performing a rapid thermal oxidation (RTO) anneal. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
-
Specification