Patent · US Expired

Method for fabricating an asymmetric channel doped MOS structure

US5891782A · kind A · utility

21Cited by
5References
16Claims
0Family size

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Key dates

Filing dateAug 21, 1997
Grant dateApr 6, 1999
Priority date
Expiry dateAug 21, 2017

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH10D30/6757

Abstract

A method of forming a MOS transistor without a lightly doped drain (LDD) region between the channel region and drain is provided. The channel region is formed from a tilted ion implantation after the deposition of the gate oxide layer. The tilted implantation forms a relatively short channel length, with respect to the length of the gate electrode. The position of the channel is offset, and directly adjoins the source. The non-channel area under the gate, adjacent the drain, replaces the LDD region between the channel and the drain. This drain extension acts to more evenly distribute electric fields so that large breakdown voltages are possible. The small channel length, and eliminated LDD region adjacent the source, act to reduce resistance between the source and drain. In this manner, larger I.sub.d currents and faster switching speeds are obtained. A MOS transistor having a short, offset channel and drain extension is also provided.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.