Semiconductor device

Abstract

The semiconductor device 100 includes: a gate electrode 126 disposed in the trench 122 and facing the p-type base region 116 via the gate insulating film 124 at a sidewall portion; a shield electrode 130 disposed in the trench 122 and , is located between the gate electrode 126 and the bottom of the trench 122; the electrically insulating region 128 in the trench 22 extends between the gate electrode 126 and the shielding electrode 130, and further along the sidewall of the trench 122 and the bottom of the trench After the expansion, the shielding electrode 130 is separated from the side wall and the bottom of the groove; and the source electrode 134 electrically connects the n+ type source region 118 to the shielding electrode 130, wherein the shielding electrode 130 has: a high resistance region 130a, which is arranged on and the low-resistance region 130 is provided at a position sandwiched by the high-resistance region 130a. It is possible to suppress ringing and surge voltage, suppress erroneous operation, and prevent an increase in switching loss.

Description

technical field [0001] The present invention relates to semiconductor devices. Background technique [0002] Conventionally, a semiconductor device having a structure called a gate shield (Shield Gate) has been widely known (for example, refer to Patent Document 1). As shown in FIG. 21(a), a conventional semiconductor device 900 includes: a semiconductor base 910 including: an n+ type drain region 912, an n− type drift region 914, a p type base region 916, and an n+ type source region 918 Trench (Trench) 922, has: be formed in semiconductor substrate 910, and the trench bottom adjacent to n-type drift region 914, and adjacent to p-type base region 916 and n-type drift region 914 connected sidewall, and formed in a stripe (Stripe) shape from a plan view; the gate electrode 926 is arranged in the trench 922, and is opposed to the p-type base region 916 via the insulating film 924 at the sidewall portion; The shielding electrode 930 is arranged in the trench 922 and is locate...

AI Technical Summary

Problems solved by technology

[0007] However, once a high-resistance shield electrode is used as the shield electrode as described above, in the second half of the switching cycle, since a potential difference occurs along the wiring of the shield electrode, the gate-source capacitance C GS (Refer to Figure 20, it is the same situation in Figure 2) Gate voltage V GS It will rise suddenly, so there is a problem of easy operation error (self-turn-on (Self Turn-On)) (refer to symbol A in Figure 2(b))

In addition, due to the slow switching speed (see Figure 2(b)), there is also the problem of increased switching loss

[0008] On the other hand, if a low-resistance shield electrode is used as the shield electrode (see Fig. 3(a)), since the potential change of the drain electrode cannot be moderated when the switch is turned off, it is impossible to obtain ringing suppression at the same time. Effect of reducing surge voltage (see Figure 3(b))

Images