JPH0472768A - Self-arc suppressing type semiconductor device - Google Patents

Abstract

PURPOSE:To obtain a self-arc suppressing type semiconductor device excellent in yield by a method wherein at least a single gate and a cathode or a source are made to constitute blocks, and the blocks are electrically isolated from each other. CONSTITUTION:A rectangular gate layer 5 and a collecting gate layer 11 are electrically isolated from each other, and an N<-> base layer 2 is interposed between the gate layer 5 and the collecting gate layer 11. An insulating layer 9a is provided to a part of the surface of the N<-> base layer 2 and a part of the surface of the collecting gate layer 11, and the collecting gate layer 11 and the rectangular gate layer 5 are electrically connected together with a gate electrode of aluminum or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to self-extinguishing semiconductor devices such as static induction thyristors and static induction transistors.

B1 Summary of the Invention The present invention provides an anode or drain layer made of a P-type semiconductor formed on an N base layer made of an N-type semiconductor, a gate part made of a P-type semiconductor, and a cathode or source made of an N-type semiconductor, which are alternately arranged. In the semiconductor device, a plurality of blocks are formed by at least one gate and a cathode or source, and these blocks are electrically isolated, thereby obtaining a self-turn-off type semiconductor device with a high yield.

C1 Conventional technology In recent years, in the field of power semiconductors, improvements in the efficiency of applied equipment,
From the perspective of reducing noise, there is an increasing demand for devices that can handle higher frequencies.

In particular, static induction type semiconductor devices, such as static induction thyristors (SL thyristors) and static induction transistors (SIT), are recognized for their superior high-frequency characteristics compared to other power devices. Demand is currently increasing.

5 and 6(A) to 6(C) show a conventional electrostatic induction thyristor (Sl thyristor). Figure 5 shows S
A plan view of the main part of Cyrisk, Figure 6 (A) is A of Figure 5
-A sectional view, FIG. 6(B) is a sectional view taken along line BB in FIG. 5, and FIG. 6(C) is a sectional view taken along line C-C in FIG. 5.

In FIG. 5 and FIG. 6(A) to FIG. 6(C), l
is an anode layer made of a P layer, 2 is a base layer made of an N- layer, 3 is a channel made of an N layer, 4 is a cathode layer made of N11, 5 is a gate layer made of a P layer, and 6 is provided in the cathode layer 4. The cathode electrode 7 is made of a metal layer provided on the gate layer 5, and is made up of a strip-shaped gate electrode portion 7a and a current collecting gate electrode portion 7b.

8 is a channel electrode, 9 is an insulating film, and 10 is a flow lining P-type layer.

In addition, FIGS. 7(A) to 7(C) show conventional static induction transistors (SIT), and FIG. 7(A) shows the 6th
Corresponding to figure (A), figure 7 (13) is shown in figure 6 (B),
FIG. 7(C) corresponds to FIG. 6(C), and the same members are given the same reference numerals. Figures 7(A) to 7(C)
), 11 is a drain layer made of an N0 layer, 12 is a source layer made of an N layer, and 13 is a source electrode.

Among electrostatic induction devices, surface gate type S transistors and Sl thyristors, which are advantageous for high frequencies,
In the SI transistor, the gate 5 made of a P-type diffusion layer and the cathode 4 made of an N-type semiconductor (SI) have sources 12 arranged alternately in a strip shape, and a multi-emitter structure in which a plurality of unit devices are arranged in parallel is adopted. The dimensions of the cathode 4 of the Sl thyristor and the source 12 of the Sl transistor are as follows:
From the viewpoint of forward blocking ability and switching characteristics, the width is 2 to 1
Oh! , the length is generally about 0.2 to 5xyx.

Typically, static induction devices have either a cathode 4 or a source 1
500 A/cm” -1000 A/ for the area of 2
It is possible to control the current in cm”.

For example, Sl with a cathode of width 5μ and length 2111
In the case of a thyristor, a device with a controllable current of 100 A has about 1,000 to 2,000 cathodes, and approximately the same number of comb-shaped gate fins is required. In other words, in a surface-gate electrostatic induction device, there are many PN junctions composed of a P-type gate and an N-type channel (1000 to 2000 in the case of the above-mentioned Sl thyristor) when viewed from the A-A cross section in Figure 5. ) will be formed.

D0 Problems to be Solved by the Invention The above-mentioned PN junction maintains a reverse voltage between the gate and cathode (between the gate and source) and is reverse biased at the same time, so that a depletion layer spreads in the channel region and the voltage between the anode and cathode (between the drain and source) increases. It has the role of transitioning from a conductive state to a forward blocking state. Therefore, there is a defect D in this joint part.
(Lattice defect.

abnormal diffusion, defects caused by masks, etc.) occur,
Not only the withstand voltage between the gate and cathode (between the gate and source) but also the forward blocking voltage decreases.

For example, even if the yield of one PN junction is 99.99%, if the number of PN junctions is 2000, then (0,999%)
9)′. ``=0.135, the yield is 13.5%, and there is a problem in that the yield decreases significantly as the controllable current increases.

The present invention has been made in view of the above-mentioned problems, and its purpose is to separate the comb-shaped gate of a Sl thyristor or Sl) transistor into a strip-shaped gate part and a current collecting gate part, and to provide an insulating film between the two. It is an object of the present invention to provide a self-arc-extinguishing semiconductor device which improves the yield by providing a semiconductor device and electrically connecting it with a metal layer.

81 Means and Effects for Solving the Problems In order to solve the above-mentioned problems, the present invention provides an anode or drain layer made of a P-type semiconductor formed on an N base layer made of an N-type semiconductor, and an anode or drain layer made of a P-type semiconductor. Gate part and N
In a semiconductor device in which cathodes or sources made of type semiconductors are alternately arranged, a plurality of blocks are formed by at least one gate and cathodes or sources, and these blocks are electrically separated, thereby separating the divided gates and cathodes. The gate and cathode (source) of the part with a healthy withstand voltage between them (source) are connected with a metal electrode and operated in parallel.

F. EXAMPLES Examples of the present invention will be described below with reference to FIGS. 1 to 4.

1 is a partial plan view of a self-arc-extinguishing semiconductor device according to an embodiment of the present invention, FIG. 2(A) is a sectional view taken along the line AA in FIG. 2(C) is a sectional view taken along the line C--C in FIG. 1.

That is, FIG. 2(A) to FIG. 2(C) show the Sl thyristor according to the embodiment of the present invention, and FIG. 6(A) to FIG.
The same or equivalent parts as those in FIG. 6(C) are given the same reference numerals.

In this example, the comb-shaped gate of the Sl silice made of P-type semiconductor is separated into a strip-shaped gate part and a gate current collector part, and the two are connected by a metal layer via an insulating layer. This is a characteristic feature. In other words, Figure 2 (
As shown in B), a strip-shaped gate layer 5 and a current collecting gate layer 1
1 is separated, and an N-base layer 2 is interposed between the separated gate layer 5 and current collecting gate station l1. Part of the surface of the gate layer 5, the surface of the N-base layer 2, and the current collection gate! An insulator 89a is provided on a part of the surface of jJ11, and the current collecting gate layer 11 and the strip-shaped gate layer 5
are electrically connected by a gate electrode 7 made of metal such as aluminum (1').

In the Sl thyristor of this example, in the step before forming the metal electrode, the withstand voltage between the gates is measured for each gate, the position of the defective gate is memorized, and the electrode is applied only to other healthy parts. Defect M is generated by removing at least a portion of the defective gate and the cathode metal electrode adjacent to the gate after forming the electrode on the entire surface, and electrically separating it from other healthy portions. However, it is possible to prevent deterioration of the characteristics of the Sl silicon risk.

If the present invention is adopted as described above, even if a defect occurs in the PN junction formed by the gate and the channel, the cathode part adjacent to the gate whose characteristics are dominated by this gate part and the PN junction part Since it can be electrically isolated from other healthy parts, defects caused by defects can be removed. As a result, the yield can be improved compared to the conventional method 6. As a result of comparing the yields of the conventional and prototype Sl silices according to this example, the yield was improved by about 30% when the present invention was applied compared to the conventional one.

3(A) to 3(C) show examples in which the present invention is applied to SI transistors, and FIG. 3(A) is the embodiment shown in FIG.
A), FIG. 3(B) corresponds to FIG. 2(B), FIG. 3(C) corresponds to FIG. 2(C), and FIG. 3(A)
〜SI transistor shown in FIG. 3(C) is also shown in FIG. 2(A)
- It is constructed in the same manner as the Sl thyristor shown in FIG. 2(C), and has similar functions and effects.

According to the Sl side risk and Sl) run risk according to the above embodiment, the gate and cathode (source) are connected to each other for all gates.
Although it is necessary to check the voltage between the gates, it is possible to remove only the defective parts and effectively operate all healthy parts in parallel, so it is an effective method when the number of gates is small or there are many defects. .

FIG. 4 shows another embodiment of the present invention. In this embodiment, the gate portion has a comb-shaped gate shape like the conventional one, but the gate of the entire device is P like the conventional one.
It is characterized in that a plurality of comb-shaped gates (four in FIG. 4) are arranged independently of each other, rather than being connected by a type semiconductor layer. In this case, measure the quality between the gate and cathode (source) for each comb-shaped gate, and either do not form an electrode on the entire gate and cathode (source) of the defective comb-shaped part, or By cutting the metal wiring so that it can be electrically isolated from the comb-shaped part,
As in the above-described embodiments, even if a defect occurs, it is possible to prevent the characteristics from deteriorating.

According to the embodiment shown in FIG. 4, it is only necessary to check the withstand voltage between the gate and cathode (source) for each block of comb-shaped gates, so the advantage is that the measurement is simpler than in the embodiments described above. There is. In this case, if independent metal electrodes are formed for each block in advance, it is possible to check the withstand voltage between the gate and cathode (source) after forming the electrodes, and finally connect the healthy parts with bonding wires, etc. allows parallel operation. If the total area of the cathode is designed to be large in advance in consideration of the number of defective blocks, even if a defect occurs, the device can be operated without reducing the current rating.

G9 Effects of the Invention The present invention is as described above, and provides an N-type semiconductor made of an N-type semiconductor.
In a semiconductor device in which an anode or drain layer made of a P-type semiconductor formed in a base layer, a gate part made of a P-type semiconductor, and a cathode or source made of an N-type semiconductor are arranged alternately, at least one gate and a cathode or source are arranged. By forming multiple blocks and electrically separating these blocks, it is possible to connect the gate and cathode (source) of the portion with a healthy withstand voltage between the divided gate and cathode (source) using a metal electrode. Since they are operated in parallel, a self-extinguishing semiconductor device with high yield and high reliability can be obtained.

[Brief explanation of drawings]

FIG. 1 is a plan view of a self-arc-extinguishing semiconductor device according to an embodiment of the present invention, FIGS. (A) is the first
Figure 2 (B) is a sectional view taken along line A-A in Figure 1, Figure 2 (C) is a sectional view taken along line C-C in Figure 1, Figure 2 (B) is a sectional view taken along line C-C in Figure 1,
3(A) to 3(C) show the case where the present invention is applied to an inductive transistor, FIG. 3(A) is a sectional view taken along the line A-A in FIG. BB line sectional view of Figure 1, 3rd
FIG. 4 is a partial plan view showing another embodiment of the present invention; FIG. 5 is a partial plan view of a conventional self-arc-extinguishing semiconductor device; Figures 6(A) to 6(C)
) shows a conventional induction thyristor, and FIG.
Figure 6 (CB) is a sectional view taken along the line BB in Figure 5, Figure 6 (C) is a sectional view taken along the line CC in Figure 5, Figure 6 (CB) is a sectional view taken along the line CC in Figure 5,
7(A) to 7(C) show conventional induction transistors, and FIG. 7(A) is a sectional view taken along line A-A in FIG. 5, and FIG.
B) is a sectional view taken along the line B-B in FIG. 5, and FIG. 7(C) is a sectional view taken along the line CC in FIG. DESCRIPTION OF SYMBOLS 1... Anode layer, 2... Base layer, 3... Channel, 4... Cathode layer, 5... Gate layer, 6...
... Cathode electrode, 7... Gate electrode, 8... Channel electrode, 9... Insulating film, 9a... Insulating layer, 10
... Flow lining P-type layer, 1... Gate current collecting layer, 2... Dray current layer, 3... Source electrical layer, 4... Source electrical wire. 1 other person AA sectional view A-AIF sectional view Figure 4 Other embodiments of the present invention AA sectional view AA sectional view

Claims (1)

[Claims] (1) P on one main surface of an N-base layer made of an N-type semiconductor.
In a semiconductor device, an anode layer made of a type semiconductor is formed, and a gate part made of a P type semiconductor and a cathode part made of an N type semiconductor are alternately arranged on the main surface opposite to one main surface of the N base layer. . A self-arc-extinguishing semiconductor device, characterized in that the gate portion and the cathode portion are divided into a plurality of parts and electrically isolated from each other. (2) P on one main surface of the N base layer made of N-type semiconductor
In a semiconductor device, a drain layer made of a type semiconductor is formed, and a gate part made of a P type semiconductor and a source part made of an N type semiconductor are alternately arranged on the main surface opposite to one main surface of the N base layer. . A self-extinguishing semiconductor device, characterized in that the gate part and the source part are divided into a plurality of parts and electrically isolated from each other. (3) An anode layer made of a P-type semiconductor is formed on one main surface of an N-base layer made of an N-type semiconductor, and an anode layer made of a P-type semiconductor is formed on the main surface opposite to the one main surface of the N-base layer. In a semiconductor device in which a gate part and a cathode part made of an N-type semiconductor are arranged alternately, the gate part and the cathode part are divided into a plurality of parts to form a plurality of blocks, and these blocks are electrically isolated from each other. A self-extinguishing semiconductor device characterized by: (4) P on one main surface of the N-base layer made of N-type semiconductor
In a semiconductor device, a drain layer made of a type semiconductor is formed, and a gate part made of a P type semiconductor and a source part made of an N type semiconductor are alternately arranged on the main surface opposite to one main surface of the N base layer. . A self-extinguishing semiconductor device, characterized in that the gate section and the cathode section are divided into a plurality of blocks to form a plurality of blocks, and these blocks are electrically isolated from each other.