RF-LDMOS (radio frequency laterally diffused metal oxide semiconductor) self-alignment drain terminal field plate structure and fabrication method thereof

Abstract

The invention discloses an RF-LDMOS (radio frequency laterally diffused metal oxide semiconductor) self-alignment drain terminal field plate structure, which comprises an electrode layer (1), a substrate (2), an epitaxial layer (3), a source electrode-substrate connecting layer (4), a drift region (5), a fixed potential region (7), a source electrode (8), a channel (9), a drain electrode (15), an insulating layer (10), a grid electrode (20), a grid electrode metal silicide (21), and a source electrode-channel connecting region (22), and further comprises an SiO2 layer (23), amorphous silicon (12) and a metal silicide (17), wherein the amorphous silicon (12) comprises a transversely extending structure and a longitudinally extending structure, the longitudinally extending structure is contacted with the drift region (5), and the transversely extending structure is arranged on the SiO2 layer (23); and the metal silicide (17) is arranged on the amorphous silicon (12). The RF-LDMOS self-alignment drain terminal field plate structure can improve breakdown voltage of devices, reduces the hot carrier effect, reduces drifting of quiescent current, and obviously reduces Cds capacitance.

Description

technical field [0001] The invention relates to the field of RF-LDMOS (radio frequency laterally diffused metal oxide semiconductor), in particular to an RF-LDMOS drain terminal field plate structure and a manufacturing method thereof. Background technique [0002] The efficiency of RF LDMOS transistors mainly depends on the on-resistance and output capacitance of the transistor. In addition, the video bandwidth of the transistor also has a great relationship with the output capacitance of the transistor. Low output capacitance enables high video bandwidth. Such as figure 1 As shown, the output capacitance of the transistor mainly depends on the width of the drift region (NLDD) 5 and the drain 15 . The width of the drift region (NLDD) is determined by the breakdown voltage. For 28V RF LDMOS devices, the width of NLDD is usually required to be 3um. The width of the drain 15 is determined by the CT34 and the metal silicide 30. The metal silicide 30 needs to completely cove...

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Problems solved by technology

Because of this, the width of the drain 15 is usually relatively wide, which seriously increases the output capacitance

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