Local soi LDMOS device for frequency boosting overcoming short channel effect

Abstract

The invention discloses a local ultra-thin SOI LDMOS device which overcomes the short channel effect and increases the frequency, and belongs to the field of semiconductor devices. Including semiconductor substrate 1, channel region 2, drift region 3, source region 4, drain region 5, gate oxide 6, field oxygen 7, gate 8, channel substrate heavily doped region 9, BOX layer 18, sidewall 19. The source extension region 20, wherein the drift region 3 is a lateral variable doping structure, characterized in that a through groove is opened along the width direction of the drift region at one end of the BOX layer close to the drift region, and the BOX layer 18 is located at the side of the channel Directly below, or directly below the channel and part of the source region, or directly below the channel and the source region, to ensure the breakdown voltage while improving the frequency characteristics and drive capability of the device. The invention effectively suppresses the short-channel effect, and improves the frequency characteristic and driving ability while ensuring the breakdown voltage.

Description

technical field [0001] The invention belongs to the field of semiconductor devices and relates to a small-sized laterally diffused metal oxide semiconductor field effect transistor (LDMOS), in particular to a local ultra-thin SOI LDMOS device which overcomes the short channel effect and improves the cut-off frequency. Background technique [0002] The rapid development of wireless communication systems, power switch modules and related technologies promotes the rapid development of power integrated circuits. As the operating frequency becomes higher and higher, the requirements for circuit and device frequency are getting higher and higher. In RF power devices, LDMOS (Laterally Diffused Metal Oxide Semiconductor Field Effect Transistor) devices play an important role in RF power devices due to their good process compatibility and excellent performance. [0003] SOI RF LDMOS devices are widely used in the radio frequency field because of their good electrical insulation, low ...

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Problems solved by technology

However, the variable doping structure in the drift region cannot suppress the deterioration of short channel characteristics brought about by the reduction of device feature size, nor can it achieve a significant improvement in frequency characteristics.

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