JPS63236360A - Gate turn-off thyristor - Google Patents

Abstract

PURPOSE:To obtain a gate turn-off thyristor (GTO) having a gate electrode structure suitable for the improvement of a breaking strength by a method wherein plural pieces of ring-shaped gate current collecting electrode plates are provided in such a way as to adjoin each of the multiple rings of cathode emitter layers arranged on a circular semiconductor substrate and a plurality of regions extended radially to the periphery of the substrate from its central part are provided in such a way that the gate current collecting electrode plates are mutually coupled with a gate electrode. CONSTITUTION:N-type cathode emitter layers 2 are arranged on a circular semiconductor substrate 1 in a sextuple ring-shaped radial form and a gate electrode is provides on a P-type cathode base layer to be exposed on their peripheries in such a way as to encircle the layers 2. The gate electrode has ring-shaped gate current collecting electrode plates 10 adjacent to each ring of the layers 2, regions 11 extended radially to the periphery part of the substrate 1 from its central part in such a way that the electrode plates 10 are mutually coupled with the gate electrode and a gate current collecting electrode plate 12 on the central part of the substrate. According to this structure, the resistance of the gate electrode can be uniformized in the whole within the surface of a large-diameter GTO element. Therefore, as the numerous unit GTOs are operated uniformly, the breaking strength can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a gate turn-off thyristor (hereinafter abbreviated as GT○), and particularly to an element structure suitable for improving cut-off withstand capability.

[Conventional technology]

GTO generally has a semiconductor substrate in which a large number of units GT◯ are arranged. To improve the cut-off withstand capacity, all units GTO
It is necessary to operate the GTO uniformly, and in order to do this, the gate electrode resistance within the GTO element plane must be made uniform, and each unit GTO
It is necessary to uniformly supply gate signals to the As a conventional technique effective for this purpose, in a large current GTO, as described in Japanese Patent Application Laid-Open No. 59-86260, a ring-shaped gate current collector is installed in the middle of multiple rings of cathode emitter layers arranged on a circular semiconductor substrate. A structure including an electrode plate has been proposed.

[Problem that the invention seeks to solve]

In the above-mentioned conventional technology, the difference in distance between the gate current collector electrode plate in the centermost unit GTO and the outermost unit GT'O with respect to the gate current collector electrode plate becomes small, so that the difference in gate electrode resistance is reduced. Uniformity can be reduced. However, even if this conventional technology is used, large-diameter GTOs with a diameter of 701II11 or more cannot be used.
In this case, the non-uniformity of the gate electrode resistance within the device surface becomes large, making it difficult to improve the cut-off withstand capability.

An object of the present invention is to provide a GTO having a gate electrode structure suitable for improving cut-off withstand capability.

[Means for solving problems]

The above object is to provide a plurality of ring-shaped gate current collector electrode plates adjacent to each of the multiple rings of cathode emitter layers arranged on a circular semiconductor substrate, and to attach the gate current collector electrode plate to the gate electrode. This is achieved by providing a plurality of regions extending radially from the center of the circular semiconductor substrate to the periphery so as to be connected to each other.

[Effect]

According to the above structure, the gate electrode resistance can be made uniform throughout the device plane of the large-diameter GTO, so that a large number of unit GT
Since O operates uniformly, the cut-off withstand capability can be improved.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

Identical or equivalent parts in the drawings below are given the same reference numerals.

FIG. 1 is a cathode side plan view of a GTO embodying the present invention, and shows one-fourth of a circular GT○.

N-type cathode emitter layers 2 are arranged radially in a six-fold ring on a circular semiconductor substrate 1, and a gate electrode is provided on the p-type cathode base layer exposed around the base layer so as to surround the cathode emitter layers 2. . The gate electrode includes a ring-shaped gate current collector electrode plate 1o adjacent to each ring of the emitter layer 2, and the above-mentioned collector@electrode plate 10 (hereinafter referred to as ring gate).
A region 11 (hereinafter referred to as a radiation gate) extending radially from the center to the periphery of the circular semiconductor substrate 1 so as to connect the
In addition, the gate current collector electrode plate 12 (
(hereinafter referred to as center gate).

FIG. 2 is an equivalent circuit for explaining the operation of this embodiment. The part surrounded by a dashed line indicates one of the multiple rings of the cathode emitter layer 2, and the GT◯ symbol indicates a unit GTO. In order to simplify the diagram, the number of rings is two and the unit GT○ in one ring is two, but the following explanation can also be applied to a case where the number of rings and the number of unit GTOs are large. It is assumed that the center gate is connected to the external gate terminal G.

rG and rR are the electrode resistances of the center gate and radiation gate, respectively, rRl and rQ2 are the electrode resistances of the ring gate, r
t, rz, rl2 indicate the resistance of the gate electrode in the region other than each gate, and rQ, rR, rRl and rQ2 are r
The electrode pattern is designed so that the values are sufficiently smaller than l, rz, and rl2. Unit GTOa, b from gate terminal
The resistance of the gate electrodes reaching the gates of , c and d are respectively,
When calculating the difference between each resistance and ra as ra, rb, rc, and rd, when a ring gate and a radiation gate are provided, lrb ral=rRt l rC-ral = l rr+-ralI ra
-ra l = l ru+ rRz - If rGi is not provided, l rb ral=r'1 1 r'Cra l = rr+ rxzl ra-r
al = r1 + rtz + rz. As mentioned above, r
Gl rR+ rR1+ rRl<rx, r2
．． rtx, the difference between ra and each resistance becomes smaller by providing a ring gate and a radiation gate. That is, since the gate electrode resistance can be made uniform within the element surface of the GTO, the gate signal supplied to each unit GTO becomes uniform, and the uniformity of the operation is improved, which has the effect of improving the cut-off withstand capability. It should be noted that what is connected to the external gate terminal is not limited to the center gate, but may also be the ring gate or both, but especially when the center gate is connected, the package has the effect of having a simple structure and being inexpensive.

FIG. 3 is a diagram showing a GTO according to another embodiment of the present invention.

Although it is simplified in Figure 3, the actual diameter is approximately 90 mm.
Approximately 1,700 OR type cathode emitter layers 2 are arranged in an 8-layer ring on a circular semiconductor substrate 1 with a diameter of 1,700 mm, a ring gate 10 is provided for every two rings, and four gates are arranged in the direction of the arrow from the center of the circular semiconductor substrate. A radiation gate 11 is provided. In this embodiment, the n-type cathode emitter layers are arranged in a straight line in the direction of each arrow. As a result, when trimming with an automatic device, if the n-type cathode emitters arranged on the above-mentioned straight line are selected as the trimming starting point, the positions of the starting points in each ring of n-type cathode emitters will match in the angular direction. , programming becomes easier.

〔Effect of the invention〕

As described in detail above, according to the present invention, the gate electrode resistance within the device plane of the GTO can be made uniform, so that there is an effect of improving the cut-off withstand capability.

[Brief explanation of the drawing]

FIG. 1 is a cathode side plan view of a GTO according to an embodiment of the present invention, FIG. 2 is an explanatory diagram of the operation of the present invention, and FIG. 3 is a schematic diagram showing a cathode side plane of a GTO according to another embodiment of the present invention. It is. DESCRIPTION OF SYMBOLS 1...Circular semiconductor substrate, 2...N-type cathode emitter layer, 10...Ring gate, 11...Radiation gate, grass 1 solid Agi 22 grass 3 hard

Claims (1)

[Claims] 1. A semiconductor substrate having a pair of main surfaces and at least four pnpn layers forming a pn junction between adjacent ones, the first layer being divided into a plurality of strip-shaped regions, the strip-shaped regions are arranged radially and in multiple rings, the second layer and the strip-shaped regions are exposed on one main surface of the semiconductor substrate;
In the gate turn-off thyristor, a cathode electrode is provided on the strip-shaped region, a gate electrode is provided on the second layer, and an anode electrode is provided on the other main surface of the semiconductor substrate, wherein a plurality of ring-shaped gates are provided on the gate electrode. A current collector electrode plate is provided adjacent to each of the multiple rings of the strip-shaped region, and the gate electrode extends from the center to the peripheral part of the semiconductor substrate connecting the plurality of gate current collector electrode plates to each other. A gate turn-off thyristor characterized by having a plurality of radially extending regions. 2. In claim 1, the multiple ring of strip-shaped regions has a region in which a plurality of strip-shaped regions are arranged in a straight line from the center to the periphery of the semiconductor substrate, and this region is A gate turn-off thyristor, characterized in that the gate turn-off thyristor is adjacent to a region of a gate electrode that connects the ring-shaped gate current collector electrode plate.