JP3334509B2 - Semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device such as a gate turn-off thyristor (hereinafter, referred to as a GTO thyristor).

[0002]

2. Description of the Related Art FIG. 14 and FIG.
FIG. 1 is a sectional view and a plan view showing a conventional GTO thyristor disclosed in Japanese Patent No. 4033. In the figure, reference numeral 1 denotes a semiconductor substrate having one main surface 11 and the other main surface 12 and having different conductivity types so as to form a pn junction between adjacent ones, and is exposed to the one main surface 11. The cathode-side N emitter layer 13 and the P base layer 14, the N base layer 15 adjacent thereto, and the anode-side P emitter layer 16 exposed on the other main surface 12 constitute four layers. The N emitter layer 13 includes a plurality of radially elongated regions separated from each other by the P base layer 14, and these regions are arranged radially and concentrically. 2 is an anode electrode deposited on the P emitter layer 16, 3 is a plurality of cathode electrodes deposited on each region of the N emitter layer 13, 4 is an N electrode layer 13
P base layer 14 so as to continuously surround each region of
A plurality of gate electrodes 5 having a thickness of about 10 μm, a cathode extraction metal 5 electrically contacting the plurality of cathode electrodes 3, 6 electrically connected to an outer peripheral side of the gate electrode 4, 4 is a gate terminal for introducing a gate signal.

In such a conventional GTO thyristor, when a gate current flows from the gate electrode 4 to the cathode electrode 3 in the forward direction, the state changes from the off state to the on state, and conversely,
When a gate current flows from the cathode electrode 3 to the gate electrode 4 in the reverse direction, the state shifts from the ON state to the OFF state, and the self-extinguishing is performed. In order to obtain good turn-off characteristics, the N emitter layer 1
3 is divided into a large number of independent islands having a small width, and the ON current of the P emitter layer 16 is extracted from the gate electrode 4 continuously surrounding each region of the N emitter layer 13. Further, the ON current taken out to the gate electrode 4 is discharged outside from the gate terminal 6 electrically connected to the outer periphery of the gate electrode 4, and the GTO thyristor is turned off.

[0004]

Since the conventional GTO thyristor is configured as described above, when the thyristor is turned off, the current absorbed by the gate electrode 4 is reduced to the portion where the gate terminal 6 is connected. It will flow in the gate electrode 4 in the horizontal direction. However, the gate electrode 4 has 10
Since the cathode electrode 3 is formed by vapor deposition as thin as about μ, there is a large difference in the resistance value from the surrounding gate electrode 4 region to the gate terminal 6 depending on the inner and outer radial positions of the cathode electrode 3. Will happen. For this reason, Japanese Patent Application Laid-Open
A gate lead is provided to increase contact with a gate electrode as shown in Japanese Patent No. 51275, and a ring-shaped gate ring is provided in the middle of the gate electrode as shown in Japanese Patent Publication No. 63-58376. There is,
In each case, only the contact area with the gate electrode was locally increased, and the uniform turn-off operation in each region was not sufficient, and this was an obstacle to greatly improving the cut-off withstand capability.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and a first object of the present invention is to provide a semiconductor device which can further improve the turn-off operation in each region and can greatly improve the cut-off resistance. is there. A second object of the present invention is to provide a semiconductor device capable of reliably pressing the entire surface of the gate extraction metal facing substantially the entire surface of the gate electrode against the gate electrode. A third object of the present invention is to provide a semiconductor device which can surely hold a gate extraction metal and an insulator on a cathode extraction metal and can improve assemblability. A fourth object is to provide a semiconductor device capable of uniformly pressing a gate extraction metal to a gate electrode. A fifth object is to provide a semiconductor device which can easily manufacture a gate extraction metal.

[0006]

In a semiconductor device according to the present invention, a plate-shaped gate extraction metal is provided substantially on the entire surface of a gate electrode, and the gate extraction metal surrounds a region of a cathode electrode. A plurality of openings are provided and are electrically connected to the gate electrode.

Further, an insulator facing the plate-shaped gate extraction metal is provided between the cathode extraction metal and the gate extraction metal, and the insulator is insulated therebetween.

The cathode extraction metal protrudes a plurality of electrode portions electrically connected to the plurality of cathode electrodes, respectively, so as to face the plurality of cathode electrodes. Each of the electrode portions has an opening that is opened to face each region, and has a recess formed to face the gate electrode and faces the gate electrode, and the recess has a plate-like shape. The gate removal metal is retained.

Further, the insulator is made of an insulating material having elasticity facing the metal to be taken out of the gate, and this insulator is used to elastically press the metal to be taken out toward the gate electrode.

Further, the plate-shaped gate extraction metal has a plurality of openings which are open so as to surround a plurality of adjacent cathode electrodes.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. 1 to 5 show a GTO thyristor according to a first embodiment of the present invention.
Reference numeral 1 denotes a semiconductor substrate having one main surface 11 and the other main surface 12 and having different conductivity types so as to form a pn junction between adjacent ones. N emitter layer 13 and P base layer 14 forming the first base layer, N base layer 15 forming the second base layer adjacent thereto, and P emitter layer on the anode side exposed on the other main surface 12 16 and four layers,
The N emitter layer 13 on the cathode side corresponds to the P base layer 1.
4 and a plurality of radially elongated regions separated from each other by a radial direction, and these regions are arranged radially and concentrically. 2 is an anode electrode deposited on the P emitter layer 16, 3 is a plurality of cathode electrodes deposited on each region of the N emitter layer 13, and 4 is a cathode electrode surrounding each region of the N emitter layer 13. The P base layer 14
A plurality of gate electrodes are deposited by about 10 μm, and continuously surround each region of the plurality of cathode electrodes 3 as shown in FIG. Reference numeral 5 denotes a cathode extraction metal that is in electrical contact with the plurality of cathode electrodes 3, and has a plurality of electrode portions 5a protruding opposite to the plurality of cathode electrodes 3, respectively. It is electrically connected to the cathode electrode 3. Reference numeral 6 denotes a gate terminal which is soldered and electrically connected to the outer peripheral side of the gate electrode 4 to introduce a gate signal to the gate electrode 4.

Numeral 7 is formed in a plate shape so as to oppose substantially the entire surface of the gate electrode 4, and is opened radially and concentrically as shown in FIG. 4 so as to individually surround each region of the cathode electrode 3. This is a gate extraction metal having a plurality of openings 7a, for example, is formed to a thickness of 0.5 mm or more, is brazed to the gate electrode 4, and is electrically connected to the entire surface.

In the GTO thyristor configured as described above, when a gate current flows in the reverse direction from the cathode electrode 3 to the gate electrode 4 to perform a turn-off operation, the on-current of the P emitter layer 16 is reduced by the respective currents of the N emitter layer 13. It is extracted from the gate electrode 4 which individually surrounds the periphery of the region. The ON current extracted to the gate electrode 4 is directly absorbed by the plate-shaped gate extraction metal 7 electrically in contact with the gate electrode 4, and further flows through the gate extraction metal 7 in the lateral direction to form a gate terminal. 6 is discharged to the outside, and the GTO thyristor is turned off. In this case, the current is directly absorbed by the gate extraction metal 7 that is in electrical contact with the gate electrode 4, so that it is not necessary to flow through the gate electrode 4 of only about 10 μ in the lateral direction as in the related art. That is, the gate extraction metal 7 which is much thicker than the gate electrode 4 such as 0.5 mm or more flows in the lateral direction. Therefore, the difference in the resistance in the horizontal direction from the gate electrode 4 to the gate terminal 6 greatly depends on each arrangement position, so that the turn-off operation in each region can be improved, and the breakdown strength can be significantly improved.

Embodiment 2 FIG. In the first embodiment,
The gate extraction metal 7 is soldered to the gate electrode 4 so as to be electrically connected thereto. However, as shown in FIGS. The body 8 is opposed to the gate extraction metal 7 and bonded to the cathode extraction metal 5 to insulate between the cathode extraction metal 5 and the gate extraction metal 7, and to separate the gate extraction metal 7 via the insulator 8. If it is configured to be in pressure contact with the gate electrode 4, not only can the gate extraction metal 7 be reliably insulated from the cathode extraction metal 5, but also the entire surface of the gate extraction metal 7 facing the entire surface of the gate electrode 4 can be reliably connected to the gate electrode 4. Can be pressed against

Embodiment 3 In the second embodiment, the insulator 8 having substantially the same plane shape as the gate extraction metal 7 is bonded to the cathode extraction metal 5, but as shown in FIGS. The insulator 8 has a plurality of openings 8a that open regions facing the respective regions of the plurality of electrode portions 5a of the cathode extraction metal 5 and has a plurality of openings 8a. It is fitted to. A concave portion 8b is formed in a portion of the insulator 8 opposite to the gate electrode 4, and the concave portion 8b is formed in substantially the same plane as the plate-shaped gate extraction metal 7, and the gate extraction metal 7 Is fitted. With this configuration, the electrode portion 5a of the cathode extraction metal 5 is formed.
Since the insulator 8 is disposed except for the gate extraction metal 7
Is not only reliably insulated from the cathode extraction metal 5, but also the insulator 8 is connected to the electrode portion 5a of the cathode extraction metal 5.
In addition, the gate extraction metal 7 is securely held by the insulator 8, so that the assemblability is significantly improved.

Embodiment 4 FIGS. 10 and 11 show another embodiment in which the plate-shaped gate extraction metal 7 is pressed against the gate electrode 4. The insulator 8 is made of an elastic insulating material facing the gate extraction metal 7. And the whole surface of the gate extraction metal 7 is elastically pressed toward the gate electrode 4 by the insulator 8. If the cathode electrode 3 and the gate electrode 4 are substantially in the same plane, If the gate electrode 4 side of the gate extraction metal 7 is configured to protrude beyond the electrode portion 5a of the cathode extraction metal 5 by the dimension a as shown in FIG. 10 as shown in FIG. The entire surface of the gate extraction metal 7 can be uniformly pressed against the gate electrode 4 with a pressing force corresponding to the pressure.

Embodiment 5 FIG. 12 shows a fifth embodiment of the present invention, in which a plate-shaped gate extraction metal 7 has a plurality of radially and concentrically-opened openings surrounding a plurality of adjacent cathode electrodes 3. Opening 7a is formed. In this configuration, since the opening 7a is formed widely, the production of the gate extraction metal 7 becomes easy. Although the path of the current flowing through the plate-shaped gate extraction metal 7 may become longer, the thickness of the gate extraction metal 7 is much more than 0.5 mm compared to the thickness of the gate electrode 4 of 10 μm. Since it is large, a similar effect of enabling a uniform turn-off operation in each region is achieved.

In the above description, the cathode-side emitter layers are arranged radially and concentrically. However, the arrangement is not particularly limited.

In the above description, the cathode side emitter layer is the N emitter layer 13, and the first base layer is the P base layer 1.
4, the second base layer has the N-base layer 15 and the anode-side emitter layer has the NPNP four-layer structure like the P-emitter layer 16, but conversely, the PNPN four-layer structure has been formed. Needless to say, it can also be used.

In the above description, the present invention is applied to a GTO thyristor. However, it goes without saying that the present invention can be applied to a semiconductor device having a fine pattern such as an electrostatic induction thyristor.

[0021]

Since the present invention is configured as described above, it has the following effects.

A substantially plate-shaped gate extraction metal is provided on substantially the entire surface of the gate electrode, and a plurality of openings are formed in the gate extraction metal so as to surround the cathode electrode region. By making the connections, the turn-off operation in each region can be further improved, and the withstand voltage can be greatly improved.

Also, an insulator facing the plate-shaped gate extraction metal is provided between the cathode extraction metal and the gate extraction metal, and the insulator is insulated between the cathode extraction metal and substantially the entire surface of the gate electrode. The entire surface of the gate extraction metal can be reliably brought into pressure contact with the gate electrode.

Further, the cathode extraction metal has a plurality of electrode portions electrically connected to the plurality of cathode electrodes and protrudes opposite the plurality of cathode electrodes. Each of the electrode portions has an opening that is opened to face each region, and has a recess formed to face the gate electrode and faces the gate electrode, and the recess has a plate-like shape. Since the gate extraction metal is held, the gate extraction metal and the insulator can be securely held on the cathode extraction metal, and assemblability can be improved.

Further, the insulator is made of an insulating material having elasticity facing the metal to be taken out of the gate, and the metal to be taken out of the gate is elastically pressed toward the gate electrode by the insulator. The gate extraction metal can be pressed uniformly.

Further, since the plate-shaped gate extraction metal has a plurality of openings that surround the plurality of adjacent cathode electrodes, it is possible to easily manufacture the gate extraction metal.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a main part of a GTO thyristor showing Embodiment 1 of the present invention.

FIG. 2 is a cross-sectional view of a main part of the GTO thyristor showing the first embodiment of the present invention.

FIG. 3 is a plan view of a main part of the GTO thyristor showing the first embodiment of the present invention.

FIG. 4 is a plan view of a main part of the GTO thyristor showing the first embodiment of the present invention.

FIG. 5 is a plan view of a main part of the GTO thyristor showing the first embodiment of the present invention.

FIG. 6 is a cross-sectional view of a main part of a GTO thyristor showing a second embodiment of the present invention.

FIG. 7 is a plan view of a main part of a GTO thyristor showing a second embodiment of the present invention.

FIG. 8 is a sectional view of a main part of a GTO thyristor showing a third embodiment of the present invention.

FIG. 9 is a plan view of a main part of a GTO thyristor showing a third embodiment of the present invention.

FIG. 10 is a sectional view of a main part of a GTO thyristor showing a fourth embodiment of the present invention.

FIG. 11 is a sectional view of a main part of a GTO thyristor showing a fourth embodiment of the present invention.

FIG. 12 is a plan view of a main part of a GTO thyristor showing a fifth embodiment of the present invention.

FIG. 13 is a sectional view of a main part showing a conventional GTO thyristor.

FIG. 14 is a plan view of a main part showing a conventional GTO thyristor.

[Explanation of symbols]

Reference Signs List 1 semiconductor base, 2 anode electrode, 3 cathode electrode, 4 gate electrode, 5 cathode extraction metal, 5a electrode section, 7 gate extraction metal, 7a opening, 8 insulator, 8
a opening, 8b recess, 11 one main surface, 12
The other main surface, 13 N emitter layer, 14 P base layer, 15 N base layer, 16 P emitter layer

Claims (5)

(57) [Claims] 1. A cathode-side emitter layer having a different conductivity type so as to form a pn junction between adjacent ones,
A base layer, a second base layer, and an anode-side emitter layer; on one main surface, the cathode-side emitter layer is formed of a plurality of elongated regions separated from each other by the first base layer; A semiconductor substrate, a plurality of cathode electrodes provided on each region of the cathode-side emitter layer on the one main surface, and each region of the cathode-side emitter layer on the one main surface. A gate electrode provided on the first base layer so as to surround the cathode electrode, an anode electrode provided on the anode side emitter layer on the other main surface, and a cathode electrically connected to the plurality of cathode electrodes. Withdrawal metal,
A plate-shaped gate extraction metal, which is formed so as to face substantially the entire surface of the gate electrode and has a plurality of openings which are opened so as to surround the region of the cathode electrode, and is electrically connected to the gate electrode. A semiconductor device comprising: 2. A cathode-side emitter layer having a different conductivity type so as to form a pn junction between adjacent ones,
A base layer, a second base layer, and an anode-side emitter layer; on one main surface, the cathode-side emitter layer is formed of a plurality of elongated regions separated from each other by the first base layer; And a plurality of cathode electrodes provided on each of the regions of the cathode-side emitter layer on the one main surface, and each region of the cathode-side emitter layer on the one main surface. A gate electrode provided on the first base layer so as to surround the cathode electrode, an anode electrode provided on the anode side emitter layer on the other main surface, and a cathode electrically connected to the plurality of cathode electrodes. Withdrawal metal,
A plate-shaped gate extraction metal, which is formed so as to face substantially the entire surface of the gate electrode and has a plurality of openings which are opened so as to surround the region of the cathode electrode, and is electrically connected to the gate electrode. And a insulator formed opposite to the gate extraction metal, provided between the gate extraction metal and the cathode extraction metal, and insulating between the gate extraction metal and the cathode extraction metal. 3. A cathode-side emitter layer having a different conductivity type so as to form a pn junction between adjacent ones,
A base layer, a second base layer, and an anode-side emitter layer; on one main surface, the cathode-side emitter layer is formed of a plurality of elongated regions separated from each other by the first base layer; And a plurality of cathode electrodes provided on each of the regions of the cathode-side emitter layer on the one main surface, and each region of the cathode-side emitter layer on the one main surface. A gate electrode provided on the first base layer so as to surround the first base layer; an anode electrode provided on the anode-side emitter layer on the other main surface; A plurality of electrode portions, and the plurality of electrode portions are formed so as to face a cathode extraction metal electrically connected to the plurality of cathode electrodes and the gate electrode. An insulator having a plurality of openings formed to face each of the plurality of electrode portions and a recess formed to face the gate electrode, the insulator being held by the cathode extraction metal; And a plurality of openings formed opposite to substantially the entire surface of the gate electrode, insulated from the cathode extraction metal via the insulator, and opened to surround the cathode electrode region. And a plate-shaped gate extraction metal held in the recess and electrically connected to the gate electrode. 4. A cathode-side emitter layer having a different conductivity type to form a pn junction between adjacent ones,
A base layer, a second base layer, and an anode-side emitter layer; on one main surface, the cathode-side emitter layer is formed of a plurality of elongated regions separated from each other by the first base layer; And a plurality of cathode electrodes provided on each of the regions of the cathode-side emitter layer on the one main surface, and each region of the cathode-side emitter layer on the one main surface. A gate electrode provided on the first base layer so as to surround the cathode electrode, an anode electrode provided on the anode side emitter layer on the other main surface, and a cathode electrically connected to the plurality of cathode electrodes. Withdrawal metal,
A plate-shaped gate extraction metal, which is formed so as to face substantially the entire surface of the gate electrode and has a plurality of openings which are opened so as to surround the region of the cathode electrode, and is electrically connected to the gate electrode. And an insulating material having elasticity, provided between the cathode extraction metal and the gate extraction metal facing the gate extraction metal, insulates between them and insulates the entire surface of the gate extraction metal from the gate electrode. And an insulator elastically pressed toward the semiconductor device. 5. The semiconductor device according to claim 1, wherein the gate extraction metal has a plurality of openings that open so as to surround regions of a plurality of adjacent cathode electrodes.