JPH043114B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a light-triggered thyristor or a light-triggered electrostatic induction thyristor that has improved light trigger sensitivity than a conventional light-triggered thyristor or a light-triggered electrostatic induction thyristor. It is used as a switching element for small to medium power to high power.

[Conventional technology]

Traditionally, triggering thyristors with light has been widely used, and LASCR, Light Activated
It is a well-known fact that this technology is implemented under names such as Thyristor and Photothyristor. Conventional optically triggered thyristors generally have an amplification gate structure in which amplification thyristors are integrated. Furthermore, the inventor of the present application has already proposed an optical trigger thyristor in which an amplifying electrostatic induction thyristor or an amplifying electrostatic induction transistor is integrated to improve optical trigger sensitivity. Thyristor"
has been disclosed.

Static Induction Thyristor
The optical trigger of Thyristor (hereinafter abbreviated as SI thyristor) has already been proposed by the inventor of the present application, and has been published in Japanese Patent No. 1534149 (Japanese Patent Publication No. 1-3069) ``Semiconductor device including electrostatic induction thyristor'', No. 59-54937 "Light-quenchable salista device" and patent application 1983
−175734 “Light-triggered/Light-quenched electrostatic induction thyristor” and “Light-triggered/Light-quenched electrostatic induction thyristor” filed on August 25, 1988.
"Light-Quenched Electrostatic Induction Thyristor". An example of the structure is a direct trigger type in which light is incident on the main SI thyristor to trigger it, as disclosed in the patent application filed in 1983.
No. 54937 ``Light Quenchable Thyristor Device''. In addition, a static induction phototransistor (Static Induction phototransistor) is used as an optical trigger amplifier element.
An example of integrating a Photo Transistor (hereinafter abbreviated as SI phototransistor) or a static induction photothyristor (hereinafter abbreviated as SI photothyristor) is given in Japanese Patent Application No. 59-176957 ``Phototrigger・Light-quenching electrostatic induction thyristor”.

Most of the above-mentioned photo-triggered thyristors and photo-triggered electrostatic induction thyristors are of a type in which trigger light is incident from the cathode side. An example of the structure of the method in which the trigger light is incident from the anode side is disclosed in Japanese Patent Application No. 1983-
Only a few examples are given in No. 54937, ``Light Quenchable Thyristor Device''. Figure 11 of the present application shows the structure of an optical trigger/light quenching SI thyristor in which trigger light enters from the anode side of the main SI thyristor, which is proposed in Japanese Patent Application No. 59-54937 "Optical Quenchable Thyristor Device". This is an example. In the structural example shown in FIG. 11, a buried gate type SI thyristor and a light quenching SI phototransistor are integrated. The trigger light is a p ⁺
Injected into the SI thyristor from the anode region.
The quenching light is directly incident on the SI phototransistor for optical quenching.

[Problem that the invention seeks to solve]

As mentioned above, in conventional optically triggered thyristors, since light is incident from the cathode side, they are easily affected by light absorption in the cathode region and base region. Since the auxiliary thyristor is used, the optical amplification degree is low and the optical trigger sensitivity cannot be improved. Furthermore, in the electrostatic induction type optical trigger/optical quench thyristor shown in FIG. Therefore, there was still room for further improvement in terms of optical trigger sensitivity. The present invention aims to solve the above problems and provide a light-triggered thyristor with improved light-trigger sensitivity.

[Means for solving problems]

In the present invention, the following means are used to increase the optical trigger sensitivity of the conventional optical trigger thyristor.

(1) In order to suppress light absorption, light is incident from the anode side rather than from the cathode side, so that electron-hole pairs are most efficiently absorbed into the depleted second base layer. and generate it. In other words, light incident from the anode side is more efficient because the light easily enters the second base layer as long as it passes through the p anode layer.

(2) Furthermore, a static induction transistor gate structure, which has a feature of much higher optical amplification sensitivity than a bipolar base structure, is provided in the auxiliary amplification thyristor section. This greatly improves the low optical trigger sensitivity of the conventional bipolar-based structure.

(3) Furthermore, by introducing the amplification gate structure, the optical trigger sensitivity is improved compared to the conventional optical trigger/optical quench SI thyristor.

[Effect]

The optically triggered thyristor according to the present invention is driven by means such as an optical fiber that introduces an optical trigger pulse from the anode side and the optical trigger pulse.
It has a SIT gate structure on the anode side, and
The SIT gate structure is separated from the anode region of the main thyristor and is a part of the auxiliary amplification thyristor, and the cathode and base region of the auxiliary amplification thyristor are also provided on the cathode side. An optically triggered SI thyristor is formed as an auxiliary amplification thyristor between the anode region formed by the SIT gate structure.
That is, the optically triggered thyristor according to the present invention is
The basic structure is that the auxiliary light trigger SI thyristor for amplification and the main thyristor part of the conventional trigger thyristor are integrated. Alternatively, an electrode is provided in the base region surrounding the cathode region on the cathode side, and a structure that can be turned off by the gate is used.
The GTO thyristor structure and the amplification auxiliary light trigger SI thyristor may be combined.

Furthermore, there are various developments of the optically triggered thyristor according to the invention. For example, a SIT gate structure may be provided on the cathode side of the main thyristor or the auxiliary thyristor. In addition, in order to perform not only triggering by light but also gate turn-off by light, a photosensitive element is connected or integrally connected to the electrode terminal of the first gate portion or the second gate portion of the main thyristor. The main thyristor may be photogated and turned off by irradiating the photosensitive element with a photoquenching pulse.

When the auxiliary thyristor is irradiated with light from the anode side, the auxiliary thyristor is
A hole current is similarly injected from the p ⁺ anode region toward the first base region of the auxiliary thyristor.
The potential of the first base region decreases and at the same time an injection of electrons occurs from the n ⁺ cathode region of the auxiliary thyristor, which will be accumulated in the n ⁺ gate region of the SIT gate structure. Therefore, more holes flow from the p ⁺ anode region toward the first base region, so that the auxiliary SI thyristor is turned on by the optical trigger. When the auxiliary thyristor is turned on, the main thyristor is also triggered to amplify, and the main thyristor is also turned on.

For turn-off, an electrode is placed on the first base so that gate turn-off can be performed using light.
When adopting GTO gate structure, or
When an SI thyristor structure is adopted for the main thyristor portion, the main thyristor is turned off at high speed by electrical gate turn-off or light gate turn-off. As a matter of course,
Even in such a self-extinguishing device, a commutation circuit may be connected between the anode and the cathode and turned off by commutation turn-off.

In addition, when the main thyristor portion has the structure of a conventional four-layer optically triggered thyristor, there is a commutation turn-off.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a cross-sectional structure of an embodiment of the optically triggered thyristor of the present invention. A SIT gate structure of an auxiliary SI thyristor is provided on the anode side. That is, n ⁺ region 909 represents the gate region of the auxiliary SI co-thyristor, and p ⁺ region 910 represents the anode region of the auxiliary SI thyristor. 908 is a gate electrode, 911
is an anode electrode, and both are preferably formed of transparent electrodes. 912 is optical trigger pulse
A means such as an optical fiber for introducing the LT913 is shown. 914 indicates an insulating layer. 900 is
n ^- indicates a high resistance layer. 901 indicates a p base layer.
902 indicates the n ⁺ cathode region of the main thyristor;
903 is the n ⁺ cathode region of the auxiliary thyristor. 904 is the cathode electrode of the main thyristor, 90
5 is an electrode connected to the n ⁺ cathode region of the auxiliary SI thyristor portion, and is short-circuited to the p base layer. 9
06 is a p anode region of the main thyristor, and 907 is an anode electrode.

Next, the operation of the embodiment shown in FIG. 1 will be explained. When the main thyristor and the auxiliary SI thyristor are off, when the optical trigger pulse LT913 is irradiated from the anode side of the auxiliary SI thyristor, electron-hole pairs are generated in the n ^- high resistance layer 900, and the generated The hole in the electron-hole pair is in the p base layer 901
The electrons accumulate in the n ⁺ gate region 909. The potential for holes in the n ⁺ gate region 909 is reduced by the accumulated electrons, and the potential for holes in the n ⁺
Holes are injected from the anode region 910 into the n ^- high resistance layer 900 , and the injected holes accumulate in the p base layer 901 , reducing the potential of the p base layer 901 for electrons, and the n ⁺ cathode region 90
Electrons are injected from 3 to the n ^- high resistance layer 900, and the electrons accumulate in the n ⁺ gate region 909, and further
lowering the potential of the n ⁺ gate region 909;
The auxiliary SI thyristor turns on. Due to the hole current of the auxiliary thyristor, the p base layer 90 of the main thyristor
1 is charged, and the p anode and
The second base near the n ^- high resistance layer junction is also charged and the main thyristor is turned on. In the conventional optically triggered thyristor shown in FIGS. 9 and 10, the auxiliary thyristor is
Since it has a bipolar base structure, its photosensitivity is low, but in the embodiment of the present invention shown in FIG.
The SIT gate structure enables high-speed optical triggering with low optical intensity. In addition, by injecting light from the anode side, depleted
Light can efficiently penetrate into the n ^- high resistance layer 900, and the photosensitivity is further improved.

FIG. 2 shows a cross-sectional structure of an optically triggered thyristor according to the present invention, in which the main thyristor is a gate turn-off thyristor (hereinafter abbreviated as GTO). n ⁺ area 1010
is the gate region of the auxiliary SI thyristor, p ⁺ region 10
13 indicates the anode region of the auxiliary SI thyristor.
1011 is a gate electrode, and 1012 is an anode electrode, both of which are preferably formed of transparent electrodes. 1016 is optical trigger pulse LT101
7 is shown. 1014 indicates an insulating layer. 1000 is n ^-
High resistance layer, 1001 is p base layer, 1002 is main layer
The n cathode region of the GTO, 1007 is the n cathode region of the auxiliary SI thyristor, and 1009 is the p anode region of the main GTO. 1006 is the cathode electrode of the auxiliary SI thyristor, 1005 is the p base electrode of the auxiliary SI thyristor, 1004 is the cathode electrode of the main GTO, 1003 is the p base electrode of the main GTO, 1
008 is the anode electrode of the main GTON.

The optical trigger (optical turn-off) mechanism is the same as the embodiment of FIG. That is, when the main GTO and the auxiliary SI thyristor are off, when the optical trigger pulse LT107 is irradiated from the anode side of the auxiliary SI thyristor, electron-hole pairs are generated in the n ^- high resistance layer 1000, and the Among the generated electron-hole pairs, holes are accumulated in the p base layer 1001,
Electrons accumulate in the n ⁺ gate region 1010. The potential for holes in the n ⁺ gate region 1010 is lowered by the accumulated electrons, and holes are injected from the p ⁺ anode region 1013 into the n ^- high resistance layer 1000, and the injected holes are transferred to the p base layer. 1
001, the potential for electrons of the p base layer 1001 decreases, and the n ⁺ cathode region 1
Electrons are injected from 007 into the n ^- high resistance layer 1000, and the electrons are accumulated in the n ⁺ gate region 1010.
Further lowering the potential of the n ⁺ gate region,
The auxiliary SI thyristor turns on. Due to the hole current of the auxiliary SI thyristor, the p base layer 100 of the main GTO
1 is charged, and the second base near the p anode and n ^-high resistance layer junction is also charged by the electron current,
Main GTO turns on. In the embodiment shown in FIG.
Since the main thyristor consists of a GTO, it can be electrically gated off.
In addition, by connecting or integrating a photosensitive element to the p base electrode 1003 of the main GTO and irradiating the photoquench pulse to this photosensitive element, the main GTO can be
GTO can be gated and turned off with light.

FIG. 3 shows the cross-sectional structure of an optically triggered thyristor according to the present invention, in which the main thyristor is a single-gate buried gate SI thyristor and the amplification photosensitive element is a double-gate SI photothyristor. show.

In Figure 3, the single-gate buried gate SI thyristor, which is the main thyristor, has p ⁺
anode region 1101, n ^- high resistance region 1102,
n ⁺ cathode region 1103, p ⁺ gate region 110
4. Anode electrode 1131, cathode electrode 113
2 and a gate electrode 1133. The auxiliary SI photothyristor has p ⁺ anode region 111
1, n ^- high resistance region 1112, n ⁺ cathode region 1
113, p ⁺ gate region (first gate region) 11
14, n ⁺ gate (second gate region) 1115,
Anode electrode 1141, cathode electrode 1142,
It is composed of a second gate electrode 1144. 1
151 is an insulating layer. The anode electrode 1141 and second gate electrode 1144 of the auxiliary SI thyristor are preferably formed of transparent electrodes. The p ⁺ gate region 1104 of the main thyristor and the p ⁺ gate region 1114 of the amplifying SI photothyristor have a structure in which they are separated and a structure in which they are not separated. In a separated structure, the photosensitivity of the auxiliary SI thyristor is further improved. 1172 is the optical trigger pulse 117
This is a means such as an optical fiber for introducing 1.

In the embodiment shown in Fig. 3, the main thyristor is composed of a single gate type SI thyristor, and the auxiliary amplification thyristor is composed of a double gate type SI photothyristor, so high-speed optical triggering can be achieved with weak light. .

The optical trigger (optical turn-on) mechanism is the same as the embodiment of FIGS. 1 and 2. When the optical trigger pulse 1171 is irradiated from the anode side of the auxiliary double gate SI thyristor with the main thyristor and the auxiliary thyristor turned off, electron-hole pairs are generated in the n ^- high resistance layer 1112, and the generated The hole in the electron-hole pair is in the p ⁺ gate region 11
14, the electrons accumulate in the n ⁺ gate region 1115, and the auxiliary double gate SI thyristor turns on. The hole current from the anode of the auxiliary double-gate SI thyristor charges the p ⁺ gate region of the main SI thyristor, lowering its potential for electrons and reducing the n ⁺ cathode region 110 of the main thyristor.
Electrons are injected into the n ^- high resistance layer 1102 from 3 to turn on the main thyristor. Further, the gate can be turned off by electrically driving the gate electrode 1133 of the main SI thyristor. moreover,
By connecting or integrally connecting a photosensitive element to the gate electrode 1133 and irradiating this photosensitive element with a light quench pulse, the gate of the main SI thyristor can be rapidly turned off with light. auxiliary
The n ⁺ gate of an SI thyristor may be used in an open state or may be biased. Further, the anode of the auxiliary SI photothyristor is connected to the anode of the main SI thyristor.

FIG. 4 shows a cross-sectional structure of an optically triggered thyristor according to the present invention, in which the main thyristor is a double-gate buried gate type SI thyristor and the amplification photosensitive element is a double-gate buried gate type SI photothyristor. shows.

In FIG. 4, the main SI thyristor includes a p ⁺ anode region 101, an n ^- high resistance region 102, an n ⁺ cathode region 103, and a p ⁺ gate region (first gate) 1.
04 and n ⁺ gate region (second gate) 105 and p ⁺
anode region 101, n ⁺ cathode region 103,
Anode electrode 13 provided on exposed surface portions of p ⁺ gate region 104 and n ⁺ gate region 105
1, cathode electrode 132, gate electrode 133, 1
It consists of 34. The auxiliary SI photothyristor has a p ⁺ anode region 111 and an n ^- high resistance region 11
2 and n ⁺ cathode region 113 and p ⁺ gate region (first gate) 114 and n ⁺ gate region (second gate)
115, an anode electrode 141 and a cathode electrode 142 provided on exposed surface portions of the p ⁺ anode region 111 and the n ⁺ cathode region 113. Main SI thyristor n ⁺ gate region 10
5 and n ⁺ gate region 1 of SI photothyristor for amplification
15 are separated. Also, the main SI Sailsa
There are structures in which the p ⁺ gate region 104 and the p ⁺ gate region 114 of the amplification SI photothyristor are separated, and structures in which they are not separated. 172 is a means such as an optical fiber for introducing the optical trigger pulse 171. The main thyristor and the auxiliary SI photothyristor have a double gate structure, and the gate area of the auxiliary SI thyristor is separated from the gate area of the main SI thyristor, so the photosensitivity of the auxiliary SI photothyristor is dramatically increased. Improved speed and high sensitivity optical triggering can be realized. When the auxiliary thyristor turns on, the hole current from the auxiliary thyristor anode 111 charges the p ⁺ gate 104 of the main thyristor, lowering the potential for electrons and removing electrons from the n ⁺ cathode of the main thyristor.
is implanted into the n ^- region 102. Further, the electrons from the cathode 113 of the auxiliary thyristor and the electrons from the cathode 103 of the main thyristor are
The n ⁺ gate 105 is charged, the potential for holes is lowered, holes are injected from the p ⁺ anode 101 of the main thyristor, and the main thyristor is turned on. The anode of the auxiliary SI thyristor is
When connected to the anode of the main SI thyristor
A possible case is that it is connected to the n ⁺ gate of an SI silister. Gate turn-off can also be performed by electrically driving one or both gates of the main SI thyristor. Furthermore, by connecting or integrating a photosensitive element to the gate and irradiating the photoquenching pulse to this photosensitive element, the main
SI thyristors can be gated and turned off quickly using light.

FIG. 5 shows the cross-sectional structure of an optically triggered thyristor according to the present invention, in which the main thyristor is a double gate planar gate type SI thyristor and the amplification photosensitive element is a double gate planar gate type SI photothyristor. shows. In Figure 5, the main
The SI thyristor consists of a p ⁺ anode region 201, an n ^- high resistance region 202, an n ⁺ cathode region 203, a p ⁺ gate region 204, an n ⁺ gate region 205, a p ⁺ anode region 201, an n ⁺ cathode region 203, and a p ⁺ gate. An anode electrode 231 and a cathode electrode 23 provided on the surface exposed portions of the region (first gate) 204 and the n ⁺ gate region (second gate) 205
2, gate electrodes 233 and 234. The auxiliary SI photothyristor includes a p ⁺ anode region 211, an n ^- high resistance region 212, an n ⁺ cathode region 213, and a p ⁺ gate region (first gate) 214.
n ⁺ gate region (second gate 215, p ⁺ anode region 211, n ⁺ cathode region 213, p ⁺ gate region 214, and an anode electrode 241 provided on the surface exposed portion of n ⁺ gate region 215, cathode electrode 242, The anode electrode 241 and the gate electrode 243 are preferably formed of transparent electrodes. 272 is a means such as an optical fiber for introducing the optical trigger pulse LT271.

The cathode of the auxiliary SI photothyristor is common to the cathode of the main SI thyristor. The p ⁺ gate region 214 is the p ⁺ gate region 2 of the main SI thyristor.
04 or in common, and if separated, open or biased. n ⁺
The same applies to gate region 215. Also, the p ⁺ anode region 211 is the n ⁺ gate of the main SI thyristor,
connected to the anode. The turn-on operation is the fourth
Same as the explanation up to the figure, optical trigger pulse LT
When the auxiliary thyristor is turned on by 271, the hole current lowers the potential for electrons of the p ⁺ gate of the main thyristor, the electron current lowers the potential for holes of the n ⁺ gate, and the main thyristor turns on. Turn-off can be achieved quickly by electrically driving the first gate or second gate of the main thyristor. Furthermore, by connecting a photosensitive element to the gate electrode 243 and irradiating this photosensitive element with a light quenching pulse, the potential of the p ⁺ gate for electrons can be increased and the main thyristor can be turned off at high speed.

FIG. 6 shows a cross-sectional structure of an optically triggered thyristor according to the present invention, in which the main thyristor is a double-gate notched gate type SI thyristor and the amplification photosensitive element is a double-gate notched gate type SI photothyristor. shows. In Figure 6, the main SI thyristor has p ⁺ anode region 3
01 and n ^- high resistance region 302 and n ⁺ cathode region 3
03 and p ⁺ gate region 304 and n ⁺ gate region 30
5 and p ⁺ anode region 301, n ⁺ cathode region 3
03, p ⁺ gate region 304 and n ⁺ gate region 3
An anode electrode 331, a cathode electrode 332, and a gate electrode 33 provided on the surface exposed portion of 05
It consists of 3,334. The auxiliary SI photothyristor includes a p ⁺ anode region 311, an n ^- high resistance region 312, an n ⁺ cathode region 313, a p ⁺ gate region 314, an n ⁺ gate region 315, a p ⁺ anode region 311, an n ⁺ cathode region 313, and a p It is composed of ^an anode electrode 341, a cathode electrode 342, and gate electrodes 343 and 344 provided on the surface exposed portions of the + gate region 314 and the n ⁺ gate region 315. It is preferable that the anode electrode 341 and the gate electrode 344 are formed of transparent electrodes.
372 is a means such as an optical fiber for introducing the optical trigger pulse LT371. turn on,
The turn-off mechanism is the same as described in FIG.

FIG. 7 shows a photo-triggered thyristor according to the present invention, in which the main thyristor is a double-gate buried gate type SI thyristor, and the amplification photosensitive element is a double-gate SI photothyristor with a planar gate type on the anode side and a buried gate type on the cathode side. The cross-sectional structure of the constructed example is shown. In FIG. 7, the main SI thyristor has a p ⁺ anode region 40
1 and n ^- high resistance region 402 and n ⁺ cathode region 40
3 and p ⁺ gate region 404 and n ⁺ gate region 405
and p ⁺ anode region 401, n ⁺ cathode region 40
3. p ⁺ gate region 404 and n ⁺ gate region 40
An anode electrode 431, a cathode electrode 432, and a gate electrode 43 provided on the surface exposed portion of 5
It consists of 3,434. The auxiliary SI photothyristor includes a p ⁺ anode region 411, an n ^- high resistance region 412, an n ⁺ cathode region 413, a p ⁺ gate region 414, an n+ gate region 415, a p ⁺ anode region 411, an n ⁺ cathode region 413, and an n ⁺ gate region 415. ⁺ It is composed of an anode electrode 441, a cathode electrode 442, and a gate electrode 444 provided on the surface exposed portion of the gate region 415. 451 is an insulating layer. It is preferable that the anode electrode 441 and the gate electrode 444 are formed of transparent electrodes. 472
is a means such as an optical fiber for introducing the optical trigger pulse LT471. The turn-on and turn-off mechanisms are the same as those explained in FIGS. 4 and 5.

Figure 8 shows a photo-triggered thyristor according to the present invention, in which the main thyristor is a double-gate buried gate type SI thyristor, and the amplification photosensitive element is
A cross-sectional structure of an example constructed of SI phototransistors is shown. In FIG. 8, the main SI thyristor has a p ⁺ anode region 501 and an n ^- high resistance region 502.
and n ⁺ cathode region 503 and p ⁺ gate region (first
gate) 504 and p ⁺ gate region (second gate)
505, a p ⁺ anode region 501, an n ⁺ cathode region 503, a p ⁺ gate region 504, and an anode electrode 531 provided on the exposed surface of the n ⁺ gate region 505, a cathode electrode 532, and gate electrodes 533, 534. has been done. The auxiliary SI phototransistor includes an n ⁺ source region 513, an n ^- high resistance region 512, an n ⁺ drain region 511, a p ⁺ gate region 514, and a drain provided on the surface exposed portions of the n ⁺ drain region and the p ⁺ gate region. It is composed of an electrode 541 and a gate electrode 514.
A negative voltage is applied to the drain electrode. 55
It is desirable that the drain electrode 541 and the gate electrode 542, each of which is an insulating layer, are formed of transparent electrodes. The n ⁺ source region 513 is the main SI thyristor.
It is common to the n ⁺ gate region 505. 57
2 is a means such as an optical fiber for introducing the optical trigger pulse LT571. optical trigger pulse
The SI phototransistor is turned on by the LT571.
When turned on, the potential for holes in the n ⁺ gate region of the main thyristor, which is common with the SI phototransistor, decreases, holes are injected from the anode region 501, and the main thyristor is turned on. Turn-off can be achieved extremely quickly by applying a negative potential to the gate electrode 533.

FIG. 9 shows an example of a cross-sectional structure of a conventional optically triggered thyristor. 601 is an anode electrode, 602
603 is a p-type anode region, 603 is an n-type base layer, 6
04 is a p-type base layer, 610 is an n-type cathode region of the auxiliary amplification thyristor portion, and 605 is an n-type cathode region of the main thyristor portion. Reference numeral 607 is a cathode electrode of the auxiliary amplification thyristor portion, and is also short-circuited to the p base layer. 606 indicates the cathode electrode of the main thyristor. Optical trigger pulse LT6 introduced by optical fiber 608
09 enters from the upper surface of the cathode region 610 of the auxiliary amplification thyristor portion.
n cathode 607, p base 604, n base 6
03 and p-anode 602 is triggered by a light pulse LT 609 to activate the p-base 60 of the main thyristor.
4 is activated, the main thyristor turns on. In conventional optically triggered thyristors, turn-off is based on a commutated turn-off method, so
The disadvantage is that the turn-off time is long. The optical amplification degree of the auxiliary thyristor for amplification is p base 604
Corresponds to the optical amplification of the bipolar-based structure in the layer. This optical amplification factor corresponds exactly to the current amplification factor, but in general, in order to increase the current amplification factor of a bipolar base structure, it is necessary to make the base width thinner. FIG. 10 shows that the auxiliary thyristor portion is formed by a portion of the p base layer 704, namely the n ⁺ cathode region 710, the p base 704, the n ⁻ base 703, and the p anode 702, in order to increase the current amplification factor of the auxiliary thyristor portion. Thyristor base part 7
11 is formed thinly. The other part is the 9th
As in the conventional example shown in the figure, 701 is an anode electrode;
02 is a p-type anode region, 703 is an n ^- base layer,
704 is the p base layer, 705 is the main thyristor.
n ⁺ cathode region, 706 is the cathode electrode of the main thyristor, 710 is the n ⁺ of the auxiliary thyristor for amplification
The cathode region 707 is its cathode electrode. 708 indicates an optical fiber that introduces the optical trigger pulse LT709.

In the conventional example shown in FIG. 9 and FIG.
04 and enters the n base layer, but the n type cathode layers 610, 710 and the p base layers 604, 7
It is affected by light absorption within 04. Furthermore, in conventional optical trigger thyristors, optical amplification is performed using a bipolar base structure, so the optical amplification sensitivity is lower than optical amplification using a static induction transistor gate structure (SIT gate structure). Comparing the trends in optical amplification, in the case of the SIT gate structure, the lower the incident light intensity is, the higher it becomes, whereas in the bipolar base structure, on the contrary, the optical amplification increases as the incident light intensity increases.

FIG. 11 shows a cross-sectional structure of a conventional photo-triggered/photo-quenched electrostatic induction thyristor with an anode side photo-trigger. 801 is a cathode electrode, 802 is a cathode electrode, and 802 is a cathode electrode.
n ^- high resistance layer, 803 is p ⁺ gate region, 804 is
p ⁺ anode region, 805 is an anode electrode, 80
6, 807, 809, 810, 811 are n high resistance layers, 808 is an n ⁺ gate region, 812 is an n ⁺ gate of the quench transistor, 813 is its gate electrode, and 814 is a main electrode of the quench transistor. The electrode 815 is a p ⁺ diffusion layer and indicates the main electrode region. 816 indicates an insulating layer. 817 is an optical fiber that introduces the trigger light pulse LT860,
Reference numeral 818 indicates an optical fiber into which the quench pulse LQ 850 is introduced. Reference numeral 840 indicates a thinned region of a part of the p ⁺ anode region, and reference numeral 841 indicates an insulating layer, which serves as a non-reflective film to prevent light from entering.

However, in the conventional example shown in FIG. 11, the n ⁺ buried gate region 808 and the p ⁺ buried gate region 803 are common regions over the entire device area, and no amplification gate means such as an auxiliary thyristor is provided.

〔Effect of the invention〕

Regarding the embodiments of the present invention described above, the experimental results of the direct current optical amplification factor (current amplification factor) of the SIT gate structure will be explained while comparing them with the experimental results of the bipolar base structure.

FIG. 12 shows the dependence of the DC optical amplification degree G of the SI phototransistor on the incident light intensity Pi. Using the drain bias voltage V _D as a parameter,
At the same time, the change in the gate potential of SIPT ΔV _G is shown.

FIG. 13 shows the dependence of the DC optical amplification degree G of the bipolar phototransistor (BPT) on the incident light intensity Pi. The collector bias voltage V _C is used as a parameter, and at the same time, the change in the base potential of BPT ΔV _B is also shown.

As is clear from FIGS. 12 and 13, the dependence of the DC optical amplification G on the light intensity Pi of the SI phototransistor and the BPT are completely different. BPT
Then, the direct current optical amplification G gradually increases as the optical intensity Pi increases, but it is at most 3 at Pi=10 ² μW/cm ^2.
It is about ×10 ² . On the other hand, in ^the SI phototransistor, the DC optical amplification G tends to increase as the light intensity becomes ^{weaker .}
A G exceeding that is obtained.

As mentioned above, the SIT gate structure provides a much larger optical amplification factor (current amplification factor) than the bipolar base structure. Therefore, if the SIT gate structure is applied to the amplification gate structure of an optical trigger thyristor, a trigger thyristor with high optical sensitivity and high speed can be realized.

As an example, in the case of a 400V-10A optical trigger, when using the amplification gate structure based on the SIT gate structure according to the present invention, the turn-on delay is 1.8μs with approximately 120μW of light, and the turn-on rise time is 1.1μs.
It was hot. When an amplification gate structure based on a bipolar base structure is used instead of the SIT gate structure, the gate potential of the main thyristor is
The voltage rose only to 0.6eV and could not be optically triggered.

If the optically triggered thyristor according to the present invention is used in a switching device to which a conventional optically triggered thyristor has been applied, an extremely high-speed, highly sensitive switching device can be realized. Furthermore, it greatly expands the range of applications of optically triggered thyristors from high power to medium to low power fields, and has extremely high industrial utility value.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional structure of an embodiment of a light-triggered thyristor according to the present invention, FIG. 2 is a cross-sectional structure of an embodiment of a light-triggered thyristor according to the present invention in which the main thyristor is composed of a GTO, and FIG. 3 is a cross-sectional structure of an embodiment of a light-triggered thyristor according to the present invention. Figure 4 shows the cross-sectional structure of an optical trigger thyristor in which the main thyristor is a single-gate buried gate SI thyristor and the amplification sensing element is a double-gate SI photothyristor. The main thyristor is a double gate buried gate type SI thyristor.
FIG. 5 shows a cross-sectional structure of an embodiment in which the amplification photosensitive element is a double-gate buried gate type SI photothyristor, and the main thyristor is a double-gate planar gate type SI photo-triggered thyristor according to the present invention.
FIG. 6 shows a cross-sectional structure of an embodiment of the optically triggered thyristor according to the present invention, in which the amplification photosensitive element is a double-gate planar gate type SI photothyristor, and the main thyristor is a double-gate notched gate type SI photothyristor. Consists of thyristors,
FIG. 7 shows a cross-sectional structure of an embodiment in which the amplification photosensitive element is a double-gate cut-gate type SI photothyristor, and the main thyristor is a double-gate buried-gate type SI thyristor. Figure 8 shows the cross-sectional structure of an embodiment in which the amplification photosensitive element is a double-gate SI photothyristor with a planar gate type on the anode side and a buried gate type on the cathode side, and the main thyristor is a double-gate phototriggered thyristor according to the present invention. A cross-sectional structure of an embodiment composed of a buried gate type SI thyristor, and the amplification photosensitive element is composed of an SI phototransistor, FIG. 9 shows an example of the structure of a conventional optical trigger thyristor, and FIG. 10 shows a conventional optical trigger thyristor. Another structural example of a thyristor, Fig. 11 shows a conventional photo-triggered/photo-quenched electrostatic induction thyristor using an anode side photo-trigger, and Fig. 12 shows the dependence of DC optical amplification G of an SI phototransistor on the incident light intensity Pi. , FIG. 13 shows the dependence of the direct current optical amplification G of the bipolar phototransistor on the incident light intensity Pi. 101, 201, 301, 401, 501, 9
06,1009,1101...Main thyristor
p ⁺ (p) anode region, 102, 202, 30
2,402,502,900,1000,110
2... n ^- high resistance layer of main thyristor, 103,2
03,303,403,503,902,100
2,1103...n ⁺ (n) cathode region of main thyristor, 104,204,304,404,50
4,1104...P ⁺ gate region of main thyristor,
105, 205, 305, 405, 505...n ⁺ gate region of main thyristor, 901, 1001
...P base region of main thyristor, 131, 23
1,331,431,531,907,100
8,1131...anode electrode of main thyristor,
132,232,332,432,532,90
4,1004,1132... Cathode electrode of main thyristor, 133,233,333,433,5
33,1133...p ⁺ gate electrode of main thyristor, 134,234,334,434,534...
...N ⁺ gate electrode of main thyristor, 1003...
P base electrode of main thyristor, 111, 211,
311, 411, 910, 1013, 1111...
... p ⁺ anode region of the auxiliary thyristor, 112,
212, 312, 412, 1112...n ^- high resistance layer of auxiliary thyristor, 113, 213, 313,
413,903,1007,1113...n ⁺ (n) cathode region of auxiliary thyristor, 114,21
4,314,414,1114,1115...P ⁺ gate region of auxiliary thyristor, 115,215,
315, 415, 909, 1010, 1115...
... n ⁺ gate area of auxiliary thyristor, 141,2
41,341,441,911,1012,11
41...Anode electrode of auxiliary thyristor, 14
2,242,342,442,905,100
6,1142...Cathode electrode of auxiliary thyristor, 243,343...P ⁺ gate electrode of auxiliary thyristor, 244,344,444,908,1
011, 1144...N ⁺ gate electrode of auxiliary thyristor, 1005...P base electrode of auxiliary thyristor, 511...N+ gate electrode of auxiliary SI phototransistor
n ⁺ drain region, 512...n ^- high resistance region of auxiliary SI phototransistor, 513...n ⁺ source region of auxiliary SI phototransistor, 514...auxiliary
p ⁺ gate region of SI phototransistor, 541...
...Drain electrode of auxiliary SI phototransistor, 5
42...Gate electrode of auxiliary SI phototransistor,
171,271,371,471,571,91
3,1017,1171...Optical trigger pulse, 1
72,272,372,472,572,91
2,1016,1172...means such as optical fiber for introducing optical trigger pulse, 251,45
1,551,914,1014,1151...Insulating layer.

Claims (1)

[Scope of Claims] 1. Consists of a thyristor and an electrostatic induction type photosensitive element having a gate structure disposed on a surface of the same semiconductor substrate as the thyristor, on which the anode of the thyristor is formed, and a cathode of the thyristor. and the first main electrode of the electrostatic induction photosensitive element are electrically connected, and the anode or second base of the thyristor and the second main electrode of the electrostatic induction photosensitive element are electrically connected. A photo-triggered thyristor, wherein the thyristor is driven by a current obtained by amplifying trigger light incident on the electrostatic induction type photosensitive element from the anode side. 2. A gate turn-off thyristor, and an electrostatic induction type light source having a gate structure disposed on the same semiconductor substrate as the gate turn-off thyristor, on the surface where the anode of the gate turn-off thyristor is formed. the cathode of the gate turn-off thyristor and the first main electrode of the electrostatic induction photosensitive element are electrically connected, and the anode of the gate turn-off thyristor is electrically connected to the first main electrode of the electrostatic induction type photosensitive element; and the second main electrode of the electrostatic induction type photosensitive element, and the gate turn is caused by a current which amplifies the trigger light incident on the electrostatic induction type photosensitive element from the anode side. - A light-triggered thyristor characterized by being driven as an off-thyristor. 3 Comprised of an electrostatic induction thyristor and an electrostatic induction photosensitive element having a gate structure disposed on the surface of the same semiconductor substrate as the electrostatic induction thyristor on which the anode of the electrostatic induction thyristor is formed, and The cathode of the electrostatic induction thyristor and the first main electrode of the electrostatic induction photosensitive element are electrically connected, and the second gate or anode of the electrostatic induction thyristor and the first main electrode of the electrostatic induction photosensitive element are electrically connected. The electrostatic induction thyristor is electrically connected to the main electrode of No. 2, and the electrostatic induction thyristor is driven by a current obtained by amplifying the trigger light incident on the electrostatic induction type photosensitive element from the anode side. Light-triggered thyristor. 4. The photo-triggered thyristor according to claim 3, wherein the electrostatic induction type photosensitive element is formed of an electrostatic induction photothyristor. 5. The electrostatic induction thyristor is formed of a buried gate type electrostatic induction thyristor, and the electrostatic induction type photosensitive element is formed of a double gate type electrostatic induction photothyristor having a plane gate and a buried gate. Claim 3
The light-triggered thyristor described in section. 6. The above-mentioned claim 1, wherein the electrostatic induction thyristor is formed by a buried gate type electrostatic induction thyristor, and the electrostatic induction type photosensitive element is formed by a buried gate type electrostatic induction photothyristor. The light-triggered thyristor according to item 3. 7. The above-mentioned claim 1, wherein the electrostatic induction thyristor is formed by a planar gate type electrostatic induction thyristor, and the electrostatic induction type photosensitive element is formed by a planar gate type electrostatic induction photothyristor. The light-triggered thyristor according to item 3. 8. The above-mentioned claim 1, wherein the electrostatic induction thyristor is formed by a notched gate type electrostatic induction thyristor, and the electrostatic induction type photosensitive element is formed by a notched gate type electrostatic induction photothyristor. The light-triggered thyristor according to item 3. 9 Consisting of a double-gate electrostatic induction thyristor and an electrostatic induction type photosensitive element integrated on the surface on which the anode of the double-gate electrostatic induction thyristor is formed, The two gates and the first main electrode region of the electrostatic induction type photosensitive element are formed in a common area, and the double gate electrostatic induction thyristor is driven by a current obtained by amplifying the trigger light incident from the anode side. A light-triggered thyristor characterized by: