JPH02109366A - Integrated light-triggered and light-quenched electrostatic induction thyristor - Google Patents

Abstract

PURPOSE:To decrease the number of terminals when formed in IC form and improve the degree of freedom in using by making the width of the channels of an LTSI thyristor and an SIPT the most suitable for the best fit to the characteristic of each element. CONSTITUTION:In a normal state, electrostatic induction phototransistors(SIPT's) Q2a and Q2b are turned off and a light trigger electrostatic induction(LTSI) thyristor Q1 is also turned off. When a light trigger pulse LT is applied to the thyristor Q1 in this state, a potential barrier becomes low to turn the thyristor Q1 on. When a light quenching pulse LQ is applied to the gate of the PT Q2b in the turn-on state, the PT Q2b is turned on to turn the PT Q2a on. Thereby holes accumulated in the P<+> gate area of the thyristor Q1 are discharged through the PT Q2a and a hole current injected from a p<+> anode flows to the PT Q2a to turn the thyristor Q1 off. This light trigger/quenching electrostatic induction thyristor 1 in IC form can be equipped with three terminals and the degree of freedom can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a light-triggered/light-quenched electrostatic induction thyristor.

[Conventional technology]

Conventionally, a static induction thyristor (hereinafter referred to as an S1 thyristor) is a semiconductor device that controls the forward current of a pin diode by changing the height of the potential barrier of the channel.
It has been known. Furthermore, an optically triggered St thyristor (hereinafter referred to as an LTS I thyristor) has been proposed in which the Sl thyristor is turned on by an optical trigger. Furthermore, at the gate of the LTSf thyristor, a pin photodiode, a Schottky diode, a bipolar phototransistor, which is integrated externally or on the same chip.
It has also been proposed to connect a photothyristor or the like as a quenching photosensitive element and irradiate this photosensitive element with light to perform a photoquenching operation and turn off the LTS I thyristor. Such an optical Sl thyristor that is turned on and turned off by optical triggering and optical quenching is called an optical triggering and optical quenching static induction transistor (hereinafter referred to as an LTQSI thyristor).

Figure 3 shows the single-gate LTQSI thyristor described above.
An example of a buried gate type configuration is shown. In the same figure, LT
QSI thyristor 1 is I, TS 1 thyristor Q,
and a p-channel electrostatic induction phototransistor (hereinafter referred to as 5IPT) Qt for light quenching whose source is connected to the gate of a 1LTSr thyristor Q.

The light hv irradiated onto the surface of the LTS I thyristor Q is bent at the surface between the gate electrode and the cathode electrode and enters the inside of the device. As a result, p゛buried gate G
Electron-hole pairs are generated in the depletion layer that spreads around p'' and between p'' gate Gp° anode A. The holes generated by this light are accumulated in p'' gate region cp'', and Forward biased. Due to the electrostatic induction effect by this gate, the potential barrier height V in the channel
bi, "k are lowered and injection of electrons from the cathode region occurs. On the other hand, electrons injected from the cathode region and electrons generated by light are accumulated at the interface between the p0 anode region and the n- high resistance layer. , p゛The potential barrier height Vbi□ of holes in the anode region is lowered by △VIA, and holes are injected from the anode.The potential rise in the p゛gate '6M region Gpo turns on. When the threshold potential is exceeded, the LTS I thyristor Q turns on.

Furthermore, when 5IPTQz is irradiated with light while the LTS I thyristor Q1 is turned on, the holes accumulated in the gate H region of the LTS I thyristor Q1 in the turned on state are extracted through 5IPTQ, and the LTS I thyristor Q.

turns off.

FIG. 4 shows a conventional example of a circuit for driving the LTQSI thyristor 1 mentioned above. LTS I thyristor Q,
and 5IP (h are integrated, and the auxiliary 5IPTQ is connected to the gate of 5ITQt. Also, the auxiliary 5IP
A bias voltage V GQ I V is applied to the gate and source of TQ:I and the drain of 5ITQ2.
SQ j v and Q are connected respectively. Also, S
I T Qz, the gate of S I P T Q3, the gate of L'rSI thyristor Q, and 5IPTQ,
There is a resistor RGql + RGqt S between the drains of
and RGK are connected externally. Furthermore, the cathode of the LTS I thyristor Q1 is grounded,
An output is derived from anode A via load resistor RL.

In the above configuration, the LTSJ thyristor Q1 uses a light trigger pulse (L
It is turned on at T) and turned off when the auxiliary 5rPTQ is irradiated with a light quenching pulse (LQ). When the quench pulse (■, Q) is applied to the auxiliary 5IPTQ and the integrated 5ITQz is driven by the auxiliary 5IPTQ3, the quenching pulse (■, Q) is accumulated in the p0 gate region (Gp'' in Figure 3) of the LTS I thyristor Q1 in the on state. The holes are discharged through the integrated 5ITQ!, and the hole current injected from the p anode also flows to the integrated SIT.Thereby, the LTSI thyristor Q.

turns off.

Furthermore, as shown in FIG. 5, LTS I thyristor Q,
5iTQt-, S I with Darlington configuration at the gate of
Those connected to P TQzb are also used.

This is further integrated and is 5IPTQ.
, , SITQ, SI thyristor Q, and is called an optical amplification STT (hereinafter referred to as PASTT) 2.

The drive circuit is configured as shown in FIG.
b gate, S I T Qt-, S I P T
A gate bias voltage VG9 is applied to the common drain of Qzb.
and drain voltage V DQ are connected respectively, and 5IPT
Q! th gate, LTS I thyristor Q, and S
A resistor RG is connected between the common drains of I PTQ□*Qzb.
Q and RGK are connected externally.

[Problem to be solved by the invention]

In the conventional drive circuit described above, a plurality of bias voltages V,
,,V. 9 is required, and an external resistor RGtavR is required.
@K must be connected, making the configuration complicated, and when integrated with LTSI thyristors, the number of terminals increases, making it complicated to use.

Therefore, the present invention provides an LTS I thyristor, 5IPT, S
Our objective is to simplify the circuit configuration by optimizing IT and provide an integrated optical trigger/optical quench electrostatic induction thyristor configuration that can reduce the number of terminals when integrated.

[Means to solve the problem]

In order to solve the above problems, in the present invention, the channel width of the LTS I thyristor Q is 5IPTQzb.

By optimizing the channel width of 5ITQ, the characteristics of each element are optimized, and the gate bias V GQ + external resistor RGK in Fig. 6 is omitted, and the external terminals are configured with 3 terminals. .

[Function] In the above configuration, the photo-triggered electrostatic induction thyristor is off in the normal state. At this time, when the photo-trigger electrostatic induction thyristor is irradiated with light for photo-triggering, the height of the potential barrier is lowered and the thyristor is turned on.

On the other hand, when the gate of the electrostatic induction phototransistor is irradiated with light for optical quenching in this turn-on state,
The electrostatic induction phototransistor turns on, which turns on the electrostatic induction transistor, and the charge accumulated in the gate of the phototriggered electrostatic induction thyristor in the above turn-on state is discharged through the electrostatic induction transistor and turns it off. do.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a circuit diagram showing an embodiment of a drive circuit for a photo-triggered/photo-quenched electrostatic induction thyristor according to the present invention. In the same figure, the same parts as those described above with respect to FIG. It is attached.

In FIG. 1, an LTS I thyristor Q, a PASIT2 consisting of Darlington configuration S rTQz, and S IPTQzb, and a resistor RGq connected to the gate of S IPTQzb are integrated. PASI
By optimizing the gate structure of T2 and the gate structure of LTS I thyristor Q1, the gate bias voltage VGQ in FIG. 5 is omitted. Also, the resistor RG in Figure 5
K is also omitted. Three terminals are led out as external terminals: the anode and cathode of the LTS I thyristor Q, and the common drain of the PASIT2. In these three terminals, a drain bias voltage DQ is applied to the drain, an anode is led out as an output terminal, and a cathode is grounded.

In the above configuration, in the normal state, 5IPTQz-, S
IPTQzb is off and LTST Tthyristor Q is also turned off. In this state, L
When the TSI thyristor Q1 is irradiated with an optical trigger pulse (LT), it is turned on by the action described above.

Also, in the turned on state, 5IPTQ
When the light quenching pulse (LQ) is irradiated to the gates of , , S I PTQn is turned on, thereby 5IT (l
h- turns on.

As a result, the holes accumulated in the p"gate region of the LTS I thyristor Q, as described above, become 5I
The hole current discharged through PTQ, , and injected from the p anode also flows through 5ITQz-, turning off the LTS I thyristor Q.

Figure 2 shows switching waveforms in the drive circuit of Figure 1, with anode voltage ■A, 8oo■, anode current fa
Turn-on time T at r16A. ,,2゜8μsec
, turn-off time Tore 6.5 μsec O
) High-speed switching operation is obtained.

〔effect〕

As explained above, according to the present invention, this integrated photo-triggered/photo-quenched electrostatic induction thyristor can reduce the bias voltage and resistance without reducing the switching speed, which simplifies the configuration and allows for a three-terminal configuration. , and the degree of freedom in use can be improved.

[Brief explanation of the drawing]

FIG. 1 shows the optical trigger/light quench static t! according to the present invention. A circuit diagram showing an example of a 1-conductor thyristor. Fig. 2 is a diagram showing switching waveforms in the drive circuit of Fig. 1. Fig. 3 is a diagram showing an example of the configuration of an LTQS I thyristor. Fig. 4 is a diagram showing a conventional drive circuit. FIG. 5 is a circuit diagram showing an LTQSI thyristor equipped with PASIT, and FIG. 6 is a circuit diagram showing a conventional drive circuit using the thyristor shown in FIG. 4. ■...Light-triggered/light-quenched electrostatic induction thyristor (L
TQSI thyristor), Q,... photo-triggered electrostatic induction thyristor (LTSI thyristor), Q2... electrostatic induction transistor, Q□+Qtb... electrostatic induction phototransistor (S I PT).

Claims (1)

[Claims] Two electrostatic induction transistors having a Darlington configuration are connected to the gate of the photo-triggered electrostatic induction thyristor, and the gate of the electrostatic induction transistor and the cathode of the photo-triggered electrostatic induction thyristor are connected via a resistor. A bias voltage is applied to the common drain of the electrostatic induction transistor, and the photo-triggered electrostatic induction thyristor and the electrostatic induction transistor are irradiated with light for photo-triggering and photo-quenching, respectively, to turn on and turn off the photo-triggered electrostatic induction thyristor. An integrated optical trigger/quenching electrostatic induction thyristor characterized by being configured to.