Low bitline capacitance structure and method of making same
US6426247B1 · kind B1 · utility
Assignees
Inventors
Key dates
| Filing date | Jan 17, 2001 |
| Grant date | Jul 30, 2002 |
| Priority date | — |
| Expiry date | Jan 25, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10B12/482
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method for forming a memory device having low bitline capacitance, comprising: providing a gate conductor stack structure on a silicon substrate, said gate stack structure having a gate oxide layer, a polysilicon layer, a silicide layer, and a top dielectric nitride layer; oxidizing sidewalls of said gate oxide stack; forming sidewall spacers on the sidewalls of said gate conductor stack, said sidewall spacers comprising a thin layer of nitride having a thickness ranging from about 50 to about 250 angstroms; overlaying the gate structure with a thin nitride liner having a thickness ranging from about 25 to about 150 angstroms; depositing an insulative oxide layer over the gate structure; polishing the insulative oxide layer down to the level of the nitride liner of the gate structure; patterning and etching the insulative oxide layer to expose said nitride liner; forming second sidewall spacers over said first sidewall spacers, said second sidewall spacers comprising an oxide layer having a thickness ranging from about 100 to about 400 angstroms; and, depositing and planarizing a layer of polysilicon covering said gate structure and the sidewall spacers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.