Method for making MOS transistor with source-drain on insulating layer

Abstract

The invention discloses a method for preparing MOSFET transistor that have drain and source on insulating layer which includes: exploiting diffusing or ions injecting and extension techniques, forming low doped layer on semiconductor base surface and also forming a high doped buried layer under it; afterwards, etching the high doped layer under the source and drain with selective etching technique, filling the holes left after etching with materials to form insulating layer under source and drain. The inventive method is compatible with conventional CMOS process and has high practicability.

Description

Technical field: [0001] The invention belongs to the technical field of semiconductor integrated circuits and its manufacture, and in particular relates to a method for manufacturing a MOSFET transistor whose source and drain are located on an insulating layer. Background technique: [0002] The main device in an integrated circuit, especially a VLSI, is a metal oxide semiconductor field effect transistor (MOSFET for short). The continuous reduction of device size can improve the performance of MOSFET devices, and can greatly increase the integration density of a single chip. And with the continuous expansion of chip size, circuit functions are also increasing. Now, the geometric dimensions of MOSFETs have entered the nanometer scale. [0003] When the geometric size of MOSFET devices enters the nanometer scale, various microscopic effects appear one after another, seriously affecting the further improvement of device performance with size reduction. In order to continuou...

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Problems solved by technology

However, Superhalo doping requires a very precise doping distribution, which is difficult to achieve in the actual process; secondly, traditional bulk silicon MOSFET devices using Superhalo doping technology have large source-drain parasitic capacitance and leakage; Thirdly, since the channel is relatively highly doped, the threshold voltage swing caused by impurity fluctuations is also difficult to eliminate in Super halo doped MOSFET devices

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