Method of forming semiconductor structure and semiconductor structure

Abstract

A method of forming a semiconductor structure and a semiconductor structure. Formation of semiconductor-on-insulator (SOI) field effect transistors including a plurality of base regions having different thicknesses may be performed by selectively thinning a region of the top semiconductor layer while avoiding thinning an additional region of the top semiconductor layer. An oxidation process or an etch process may be used to thin the region of the top semiconductor layer. A patterned oxidation barrier mask or etch mask may be used to prevent oxidation or etch of the additional portion of the top semiconductor layer. A plurality of shallow trench isolation structures may be formed before or after the selective thinning process step. Multiple field effect transistors with different depletion region configurations may use multiple thicknesses of multiple patterned portions of the top semiconductor layer. For example, a partially depleted SOI field effect transistor and a fully depleted SOI field effect transistor may be provided.

Description

technical field [0001] The present disclosure relates to semiconductor devices including a plurality of semiconductor-on-insulator field effect transistors, and to methods of forming such semiconductor devices. Background technique [0002] Semiconductor-on-insulator (SOI) field effect transistors are formed by providing a semiconductor-on-insulator substrate comprising a stack, from bottom to top: a handle substrate, an insulating layer, and a top semiconductor layer, and via A plurality of shallow trench isolation structures, various doped semiconductor regions, and a plurality of gate stack structures are formed in or over them. In this way, each SOI field effect transistor has the same thickness. The device characteristics of the MOSFETs can be determined by the thickness of the MOSFETs. For example, if the depletion region within a floating body region does not extend across the entire floating body region, a partially depleted SEFIFET may be formed. Alternatively, f...

AI Technical Summary

Problems solved by technology

However, it is difficult to provide a partially depleted SOI field effect transistor and a fully depleted SOI field effect transistor within a SOI substrate in which the top semiconductor layer as a whole has the same thickness.

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