Lsi Logic Corporation

Silicon Storage Technology, Inc.

Shiuh-Luen Wang

Wen-Chin Stanley Yeh

Hieu Van Tran

Nhan Do

Parviz Ghazavi

Jiunn-Yann Tsai

Henry A Om'Mani

Chiang-Sheng Yao

An array of non-volatile memory cells with spaced apart first regions extending in a row direction and second regions extending in a column direction, with a channel region defined between each second region and its associated first region. A plurality of spaced apart word line gates each extending in the row direction and positioned over a first portion of a channel region. A plurality of spaced apart floating gates are positioned over second portions of the channel regions. A plurality of spaced apart coupling gates each extending in the row direction and over the floating gates. A plurality of spaced apart metal strapping lines each extending in the row direction and overlying a coupling gate. A plurality of spaced apart erase gates each extending in the row direction and positioned over a first region and adjacent to a floating gate and coupling gate.

Array of split gate non-volatile floating gate memory cells having improved strapping of the coupling gates

A metal silicide blocking process for preventing formation of metal silicide on a first device and allowing formation of metal silicide on elements of a second device of an integrated circuit substrate is described. The process includes forming a gate electrode above the integrated circuit substrate, forming a first dielectric layer over the gate electrode and the substrate surface, forming a second dielectric layer above the first dielectric layer, etching anisotropically the second dielectric layer to form a second spacer portion adjacent to the first dielectric layer; masking the substrate surface of the first device to protect the first dielectric layer above the first device from being removed such that the substrate surface at the second device where the metal silicide is to be formed is exposed, etching the first dielectric layer to form a first spacer portion disposed between the gate electrode of the second device and the second spacer portion, the first spacer portion extends underneath the second spacer portion such that the first spacer portion is disposed between the second spacer portion and a portion of the substrate disposed beneath the second spacer portion, exposing the substrate surface of the first device, depositing a metal layer on the substrate surface and fusing metal ions from the metal layer with silicon ions from a plurality of device elements from the portion of the substrate surface where the metal silicide is to be formed to form metal silicide contact areas above the plurality of device elements.

Effective silicide blocking

A method for hardening of gate oxide without forming low dopant concentration regions at the gate oxide-polysilicon interface is described. Polysilicon is deposited onto gate oxide followed by nitrogen implantation and annealing. At this point nitrogen concentration peaks exist at the gate oxide interfaces with the single crystal substrate and the polysilicon gate electrode. This effectively hardens the gate oxide. A third polysilicon gate electrode exists in the bulk of the polysilicon gate electrode. In the described process the region of the polysilicon layer that contains the nitrogen concentration peak is removed. An electronically active dopant may then be implanted. Alternatively, a fresh polysilicon layer may then be deposited followed by implantation of an electronically active dopant. Thus, the method of the invention avoids retardation of electronically active dopant diffusion.

Nitrogen implanted polysilicon gate for MOSFET gate oxide hardening

Growing community of inventors

San Jose, CA, United States of America

Shiuh-Luen Wang