JPH0536279Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention relates to a gate turn-off thyristor that can be controlled continuously from an off state to an on state and from an on state to an off state by inputting a signal to the gate. .

[Conventional technology]

As a conventional example of this type of gate turn-off thyristor, the structure of a reverse conduction type gate turn-off thyristor disclosed in Japanese Patent Application Laid-Open No. 115866/1982 is shown in FIGS. 3a and 3b. Figure a is a pattern diagram of the cathode electrode and gate electrode of the gate turn-off thyristor, Figure b is one of the patterns of the gate turn-off thyristor at
FIG. 3 is a cross-sectional view of a portion of a shaped emitter region.

That is, in the conventional structure shown in FIGS. 3a and 3b, the reference numeral 100 represents a semiconductor substrate having a predetermined diameter. 1a and 1b are n-type emitter regions (n _E ) separated into a large number of strip-like shapes and arranged in multiple rows in the radial direction;
2 is a p-type base region ( _pB ) adjacent to _nE regions 1a and 1b, 3 is an n-type base region ( _nB ) adjacent to _pB region 2, 4 is adjacent to n-region 3, 5a, 5b, 6, and 7 are p-type emitter regions ( _pE ), and cathodes 5a, 5b, 6, and 7 are formed in ohmic contact with these _nE regions 1a, 1b, _pB region 2, and _pE region 4, respectively. electrode, gate electrode, and anode electrode.

In addition, in the figure, the symbol θ indicates each n _E area 1 on the center side.
This is the angle between a.

In the case of the gate turn-off thyristor having this conventional structure, in order to turn off the current flowing from the _pE region 4 to the _nE regions 1a and 1b to the off state, the cathode electrode 5 must be
This is done by applying a negative voltage to the gate electrode 6 and drawing out the carriers in the p _B region 2 from the gate electrode 6. To explain this transition phenomenon to the OFF state in more detail, the holes flowing from the _pE region 4 to the _nE regions 1a and 1b, when passing through the _pB region 2, The _turn -off characteristic is caused by _the p _B
The lateral resistance component of region 2 has a large influence.

[Problem that the invention attempts to solve]

Since the conventional gate turn-off thyristor has the above-mentioned configuration, in order to increase the controllable current without impairing the turn-off characteristics, a large number of n _E regions 1a and 1b separated into strips are required.
n _E area 1a, 1
It is necessary to increase the total area of b. Therefore, one means for this purpose is to expand the width of the _nE regions 1a and 1b into a fan shape (for example, in Japanese Patent Application Laid-Open No. 60-241264
However, with such means, the lateral resistance component increases in proportion to the expanded portion, which may actually worsen the turn-off characteristics, and the radial direction Shorten the n _E area 1a, which is closer to the center of the n _E areas 1a and 1b,
And even if the angle θ is arranged small, the number of n _E regions 1a closer to the center is originally small, and the total area of these n _E regions 1a and 1b will not be significantly expanded. There was a problem.

This invention was made in order to improve these conventional problems, and its purpose is to create a gate turn-off system that can control opening and closing of a larger current without impairing the turn-off characteristics. It is to provide a thyristor.

[Means for solving problems]

In order to achieve the above object, the gate turn-off thyristor according to this invention has each n-type emitter region shaped like a strip, and a parallel portion is provided on the tip side in the radial direction of the opposite long side of the strip-like shape. The number of n-type emitter regions can be reduced by narrowing the distance between adjacent n-type emitter regions by forming them so that the width between opposing long sides narrows linearly from the parallel portion toward the center of the semiconductor substrate. This increases the ratio of the total area of the n-type emitter region on the semiconductor substrate.

[Effect]

Therefore, in this invention, since the width between the opposing long sides on the radially distal end side of the strip-like shape in each n-type emitter region does not increase, there is no risk of damaging the turn-off characteristics of the device itself; Therefore, it is possible to control the opening and closing of a large current by the amount corresponding to the increase in the total area.

〔Example〕

Hereinafter, one embodiment of the gate turn-off thyristor according to this invention will be described in detail with reference to FIGS. 1 and 2.

FIG. 1 is a pattern plan view of a gate turn-off thyristor to which this embodiment is applied, corresponding to FIG. In each figure, the same reference numerals indicate the same or corresponding parts.

In this embodiment, in each of the n _E regions 1a and 1b arranged in multiple rows on the semiconductor substrate 101, the strip-like shape is parallel to the radial direction tip side of the opposing long side of the strip-like shape. A section is provided, and from this parallel section toward the center of the semiconductor substrate 101,
By forming the width between the opposing long sides to narrow linearly and by making the mutual spacing between the adjacent n _E regions 1a and 1b as close as possible, the n _E region 1a as a whole can be improved. , 1b is increased, and as a result, the proportion of the total area occupied by n _E regions 1a, 1b on semiconductor substrate 101 is effectively increased.

That is, in the case of this embodiment, from the center 0 of the semiconductor substrate 101 to the n _E region 1 closer to this
The distance to a is r ₁ , the distance to the n _E area 1b in the following equation is r ₂ , the length of each of these n _E areas 1a and 1b is l,
Let w be the same width, and n _E area 1a with respect to the center 0
When the angle of is θ ₁ and the angle of n _E region 1b is θ ₂ ,
In the middle of both long sides of the strip-like shape of each of these _nE regions 1a and 1b, the width, that is, the pattern width, increases from the midpoint l/2 toward the center of the semiconductor substrate 101. It is formed so that it gradually narrows, and the interval between the sandwiched portions is defined as d.

In addition, in this embodiment structure, n _E region 1
When considering a, r ₁ = 5 mm, l = 3 mm, d =
0.1 mm, w = 0.36 mm, the number of arranged n _E regions 1a in the conventional example in Fig. 3a was 70, but this can be increased to 84, and the same area can be reduced to 13.5.
Similarly, when r ₂ = 8.2 mm for the n _E region 1b, the number of wires arranged in the n _E region 1b in the conventional example was 228.
This can be increased to 256 lines, and the same area can be increased by 8.2%.

In the above embodiment, the pattern width is gradually narrowed from the midpoint l/2 of both long sides of the strip-like shape in each _nE region 1a, 1b toward the center of the semiconductor substrate 101. However, the starting point at which the pattern width begins to narrow is not necessarily set at the midpoint l/2.
There is no need to do this, and each n _E area 1a,
In order to avoid an increase in the lateral resistance component of 1b, it may be set appropriately in accordance with this.

[Effect of idea]

As detailed above, according to this invention, each n-type emitter region arranged in multiple rows in the radial direction on a semiconductor substrate having a predetermined diameter has a rectangular shape similar to a rectangular shape. A parallel portion is provided on the radial direction tip side of the opposing long sides, and the width between the opposing long sides narrows in a straight line from this parallel portion toward the center of the semiconductor substrate. Since the spacing between the n-type emitter regions can be reduced, the number of n-type emitter regions disposed on a semiconductor substrate having the same diameter and, as a result, the proportion of the total area occupied by the n-type emitter regions on the semiconductor substrate can be increased. At the same time, there is no fear that the width of the n-type emitter region will expand unnecessarily and increase the lateral resistance component, and for this reason, when turning off, the n-type emitter region, which has a shape similar to a strip, The current is condensed and cut in a line at the center of the width of the parallel part over the entire length of the parallel part on the opposing long sides, preventing the current from concentrating in a dotted shape, preventing electrode damage and opening/closing control. It has excellent features such as being able to increase the available current, sufficiently improving electrical characteristics such as turn-off characteristics, and being relatively simple in structure and easy to implement.

[Brief explanation of the drawing]

FIG. 1 is a pattern plan view showing the configuration of a reverse conduction type gate turn-off thyristor to which an embodiment of the present invention is applied, and FIG. Third
Figures a and b are a pattern plan view showing the configuration of a conventional reverse conduction type gate turn-off thyristor, and a longitudinal cross-sectional view taken along line A--A of the same. 101... Semiconductor substrate, 1a, 1b... N-type emitter region (n _E region), 2... P-type base region (p _B region), 3... N-type base region (n _B region), 4
...p-type emitter region (p _E region), 5a, 5b...
... cathode electrode, 6 ... gate electrode, 7 ... anode electrode.

Claims (1)

[Scope of utility model registration request] The semiconductor substrate has a four-layer structure in which an n-type emitter region, a p-type base region, an n-type base region, and a p-type emitter region are successively formed adjacent to each other;
The n-type emitter regions are shaped like strips with long sides arranged in a radial direction, and are arranged radially in multiple rows, and a cathode electrode is provided on each of these n-type emitter regions, separated from each cathode electrode. each n
In a gate turn-off thyristor in which a gate electrode is formed on the p-type base region surrounding a p-type emitter region, and an anode electrode is formed on the p-type emitter region, a rectangular-like shape of each n-type emitter region is formed on its opposite side. A parallel portion is provided on the radial direction tip side of the long side, and the width between the opposing long sides narrows linearly from the parallel portion toward the center of the semiconductor substrate. Gate turn-off thyristor.