JP2001244453A - Optical trigger lateral bidirectional thyristor and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical trigger lateral type bi-directional thyristor which can increase an optical sensitivity at room temperature and can improve a commutation characteristic at high temperatures, and also to provide a method for manufacturing the thyristor. SOLUTION: The thyristor device includes first and second thyristors, and first and second resistors. The first thyristor has a semiconductor substrate 1 of a first conductivity type, a first anode region of a second conductivity type, a first gate region of the second conductivity type, and a first cathode region of the first conductivity type formed thereto. The second thyristor connected in antiparallel with the first thyristor has the semiconductor substrate 1, a second anode region of the second conductivity type, a second gate region of the second conductivity type, and a second cathode region of the first conductivity type formed thereto. A first temperature sensitive element is connected between the first gate region and first cathode region in parallel to the first resistor, and a second temperature sensitive element is connected between the second gate region and second cathode region in parallel to the second resistor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light-triggered lateral bidirectional thyristor and a method of manufacturing the same, and more particularly, to a technique for improving light sensitivity at room temperature and improving commutation characteristics at high temperature. And a method of manufacturing the same.

[0002]

2. Description of the Related Art FIG. 5 is a sectional view of a conventional light-triggered lateral bidirectional thyristor.

In FIG. 5, reference numeral 1 denotes an n-type semiconductor substrate;
Reference numerals 1 and 22 denote a pair of p-type anode regions formed on the main surface of the semiconductor substrate 1, respectively, 31 and 32 denote a pair of p-type gate regions formed on the first surface of the semiconductor substrate 1, 41 and 42, respectively. Is a pair of n-type cathode regions formed in the p-type gate regions 31 and 32, 51 and 52 are a pair of anode electrodes, 61 and 62 are a pair of gate electrodes, and 71 and 72 are a pair of cathode electrodes. , 81 and 82 are metal wirings, 9 is a silicon oxide film, R
1 is a resistor connecting the p-type gate region 31 and the n-type cathode region 41, R2 is a resistor connecting the p-type gate region 32 and the n-type cathode region 42, T1 and T2 are external connection terminals, and thyristor 1 is an anode. Electrode 51, p-type anode region 21, n-type semiconductor substrate 1, p-type gate region 31, gate electrode 61, n-type cathode region 41, cathode electrode 71
Is a lateral thyristor composed of an anode electrode 52, a p-type anode region 22, an n-type semiconductor substrate 1, a p-type gate region 32, a gate electrode 62, an n-type cathode region 42, and a cathode electrode 72. is there.

[0004] The operation of the conventional example configured as described above will be described. An AC voltage is applied to the external connection terminals T1 and T2, but at a certain point T1 is positive and T2 is negative. And At this time, if there is no light irradiation by the LED, both thyristors 1 and 2 are in a cutoff state,
There is no conduction between T1 and T2. Here, when light irradiation is performed by the LED, holes serving as minority carriers are generated in the n-type semiconductor substrate 1. The generated holes spread in the n-type semiconductor substrate 1 due to diffusion, and a part of the holes recombine with electrons in the n-type semiconductor substrate and disappear, but those that have entered the p-type gate region 31 as they are pass through the resistor R1. It reaches the external terminal T2. At this time, a potential rise occurs due to the resistor R1, the pn junction between the p-type gate region 31 and the n-type cathode region 41 is forward-biased, and the thyristor 1 is turned on. Since an applied AC voltage is applied, a voltage T1 is negative and a voltage T2 is positive in the next half cycle. At this time, if there is still light irradiation,
The thyristor 2 is turned on by the same mechanism as described above. Thus, if there is light irradiation, the thyristors 1 and 2 alternately conduct with respect to the AC voltage, so that the conduction state continues between T1 and T2.

[0005]

Considering the case where the light irradiation is stopped, when the current flowing through the thyristor that is conducting at that time becomes less than the holding current of the thyristor, the thyristor is turned off. Become. And T1, T
Even if the polarity between the two is reversed, this bidirectional thyristor will be in the cut-off state only if the other thyristor does not conduct and remains in the cut-off state. If one of the two thyristors is turned on and then the light irradiation is stopped and the polarity between T1 and T2 is reversed, the other thyristor does not conduct and maintains the cutoff state. This is an important characteristic for thyristors. When the commutation characteristics are poor, that is, the phenomenon that the other thyristor is turned on without maintaining the cutoff state is described. If T1 is a positive voltage and the thyristor 1 is turned on, the p-type anode region 21 When excessive holes are injected into the n-type semiconductor substrate 1 and T1 is set to a negative voltage,
Excessive holes are injected into the p-type gate region 32 of the thyristor 2, forward biasing the n-type cathode region 42 and the p-type gate region 32, and the thyristor 2 becomes conductive. Especially when the temperature is high, the mobility of holes increases,
The number of holes injected into the p-type gate region also increases, and the commutation characteristics deteriorate.

In a conventional light-triggered lateral bidirectional thyristor, it is necessary to increase the value of a resistor connected between a p-type gate region and an n-type cathode region in order to improve light sensitivity. When the resistance is increased, the commutation characteristics deteriorate. In particular, in order to satisfy the commutation characteristics even at a high temperature, the resistance has to be reduced and the photosensitivity must be sacrificed to some extent.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to improve the light sensitivity at room temperature and improve the commutation characteristics at high temperatures by using a light-triggered lateral type. An object of the present invention is to provide a bidirectional thyristor and a method of manufacturing the same.

[0008]

According to a first aspect of the present invention, there is provided an optically-triggered lateral bidirectional thyristor comprising a semiconductor substrate of a first conductivity type and a second conductivity type formed on a main surface of the semiconductor substrate. A first thyristor comprising a first anode region, a first gate region of the second conductivity type, and a first cathode region of the first conductivity type formed in the first gate region; A semiconductor substrate; a second anode region of a second conductivity type formed on a main surface of the semiconductor substrate; a second gate region of a second conductivity type; and a first conductivity type formed in the second gate region. A second thyristor, which is connected in antiparallel to the first thyristor, a first resistor connecting the first gate region and the first cathode region, and a second gate region. And the second resistor connecting the second cathode region In a light-triggered lateral bidirectional thyristor, a first temperature-sensitive element having a resistance value exhibiting a negative temperature characteristic with respect to a temperature change is disposed between the first gate region and the first cathode region. Connected in parallel with each other, and connected in parallel with the second resistor between the second gate region and the second cathode region, the second temperature sensing element having a resistance value exhibiting a negative temperature characteristic with respect to a temperature change. It is characterized by being done.

According to a second aspect of the present invention, there is provided a light-triggered lateral bidirectional thyristor, wherein the first temperature-sensitive element and the second
Are characterized by being thermistors.

According to a third aspect of the present invention, there is provided a light-triggered lateral bidirectional thyristor comprising: a semiconductor substrate of a first conductivity type; a first anode region of a second conductivity type formed on a main surface of the semiconductor substrate; A first thyristor comprising a first gate region of the second conductivity type and a first cathode region of the first conductivity type formed in the first gate region; a semiconductor substrate of the first conductivity type; A second anode region of the second conductivity type formed on the main surface of the substrate, a second gate region of the second conductivity type, and a second gate region of the first conductivity type formed in the second gate region.
A second thyristor, which is connected in antiparallel with the first thyristor; a first gate region;
In a photo-triggered lateral bidirectional thyristor comprising a first resistor connecting the cathode regions of the first and second regions and a second resistor connecting the second gate region and the second cathode region, a plurality of the first plurality connected in series. Is connected in parallel with the first resistor between the first gate region and the first cathode region, and a plurality of second diodes connected in series are connected to the second gate region and the second gate region. It is characterized in that it is connected in parallel with the second resistor between the cathode regions.

According to a fourth aspect of the present invention, there is provided a method of manufacturing a light-triggered lateral bidirectional thyristor, comprising: a semiconductor substrate of a first conductivity type; and a first substrate of a second conductivity type formed on a main surface of the semiconductor substrate. A first thyristor including an anode region, a first gate region of the second conductivity type, and a first cathode region of the first conductivity type formed in the first gate region; a semiconductor substrate of the first conductivity type; A second anode region of a second conductivity type formed on a main surface of the semiconductor substrate, a second gate region of a second conductivity type, and a second gate region of a first conductivity type formed in the second gate region. A second thyristor connected in antiparallel to the first thyristor, a first resistor connecting the first gate region and the first cathode region, a second gate region and a second Comprising a second resistor connecting the cathode regions of In a regallatal-type bidirectional thyristor, a first temperature-sensitive element having a resistance value exhibiting a negative temperature characteristic with respect to a temperature change is provided between the first gate region and the first cathode region in parallel with the first resistor. A second temperature-sensitive element having a resistance value that exhibits a negative temperature characteristic with respect to a temperature change, wherein the second temperature-sensitive element is disposed between the second gate region and the second cathode region.
A light-triggered lateral bidirectional thyristor, characterized in that it is connected in parallel with a resistor of (1).

According to a fifth aspect of the present invention, there is provided a method for manufacturing a light-triggered lateral bidirectional thyristor, comprising: a semiconductor substrate of a first conductivity type; and a first substrate of a second conductivity type formed on a main surface of the semiconductor substrate. A first thyristor including an anode region, a first gate region of the second conductivity type, and a first cathode region of the first conductivity type formed in the first gate region; a semiconductor substrate of the first conductivity type; A second anode region of a second conductivity type formed on a main surface of the semiconductor substrate, a second gate region of a second conductivity type, and a second gate region of a first conductivity type formed in the second gate region. A second thyristor connected in antiparallel to the first thyristor, a first resistor connecting the first gate region and the first cathode region, a second gate region and a second Comprising a second resistor connecting the cathode regions of In Rigarateraru bidirectional thyristor, said first diode in which a plurality of connected in series between the first gate region and the first cathode region first
And a plurality of second diodes connected in parallel with each other and connected in series with the second resistor between the second gate region and the second cathode region.

The method for manufacturing a light-triggered lateral bidirectional thyristor according to claim 6, wherein the first and second diodes connected in series are the same semiconductor substrate as the first and second thyristors. It is characterized by being manufactured in the same manufacturing process.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail.

The optical trigger lateral bidirectional thyristor of the present invention comprises a semiconductor substrate of a first conductivity type, a first anode region of a second conductivity type formed on a main surface of the semiconductor substrate, and a second conductivity type. A first thyristor including a first gate region and a first conductive type first cathode region formed in the first gate region; a first conductive type semiconductor substrate; and a main surface of the semiconductor substrate. A second conductivity type second anode region, a second conductivity type second gate region, and a first conductivity type second cathode region formed in the second gate region. A second thyristor connected in anti-parallel to the thyristor, a first resistor connecting the first gate region and the first cathode region, and a second resistor connecting the second gate region and the second cathode region. Trigger Lateral Bidirectional Sensor Composed of Resistors A resistor connected in parallel with the first resistor between the first gate region and the first cathode region, the first temperature-sensitive element having a negative temperature characteristic with respect to a temperature change in the resistor; A second temperature sensitive element whose value shows a negative temperature characteristic with respect to a temperature change is connected to the second gate region and the second temperature sensitive element.
Are connected in parallel with the second resistor between the cathode regions.

According to the present invention, by adopting such a structure, the resistance exhibits a negative temperature characteristic with respect to a temperature change, that is, at a high temperature, between the gate region and the cathode region of the thyristor in parallel with the conventional resistance. By connecting a temperature-sensitive element that has a low resistance, the resistance between the gate region and the cathode region can be increased at room temperature, improving photosensitivity, and at high temperatures, the temperature-sensitive element has a low resistance. The characteristics are improved.

Further, when the first temperature sensing element and the second temperature sensing element are both thermistors, the resistance value is parallel between the gate region and the cathode region of the thyristor in parallel with a conventional resistor. By connecting a thermistor that exhibits a negative temperature characteristic with respect to temperature changes, that is, a resistance that is low at high temperatures, the resistance between the gate region and the cathode region can be reliably increased at room temperature, and photosensitivity is reliably improved. However, at high temperatures, the resistance of the thermistor becomes low, so that the commutation characteristics are more reliably improved.

The light-triggered lateral bidirectional thyristor of the present invention comprises a semiconductor substrate of a first conductivity type, a first anode region of a second conductivity type formed on the main surface of the semiconductor substrate, and a second conductive type. A first thyristor composed of a first gate region of a first conductivity type and a first cathode region of a first conductivity type formed in the first gate region; a semiconductor substrate of the first conductivity type; A second anode region of the second conductivity type formed on the surface, a second gate region of the second conductivity type, and a second cathode region of the first conductivity type formed on the second gate region. A second thyristor connected in anti-parallel to the first thyristor, a first resistor connecting the first gate region and the first cathode region, and connecting a second gate region to the second cathode region Optical trigger lateral comprising second resistor In the bidirectional thyristor, a plurality of first diodes connected in series are connected in parallel with the first resistor between the first gate region and the first cathode region, and a plurality of second diodes are connected in series. May be connected in parallel with the second resistor between the second gate region and the second cathode region.

According to the present invention, a plurality of diodes connected in series and in parallel with a conventional resistor are connected between the gate region and the cathode region of the thyristor by adopting such a structure. The resistance between the gate and the cathode can be increased, the photosensitivity is improved, and the forward voltage of the diode is reduced at high temperatures, so that the potential rise between the gate and the cathode is reduced and the commutation characteristics are improved. It is.

The method of manufacturing a light-triggered lateral bidirectional thyristor according to the present invention includes the steps of:
A first of a second conductivity type formed on a main surface of the semiconductor substrate;
Anode region, first gate region of second conductivity type and first
A first thyristor comprising a first cathode region of a first conductivity type formed in a gate region of the first type; a semiconductor substrate of the first conductivity type; and a second thyristor formed on a main surface of the semiconductor substrate.
An anti-parallel connection with a first thyristor, comprising a second anode region of a conductivity type, a second gate region of a second conductivity type, and a second cathode region of a first conductivity type formed in the second gate region. Comprising a second thyristor, a first resistor connecting the first gate region and the first cathode region, and a second resistor connecting the second gate region and the second cathode region. In a trigger lateral bidirectional thyristor,
A first temperature-sensitive element having a resistance value exhibiting a negative temperature characteristic with respect to a temperature change is connected between the first gate region and the first cathode region in parallel with the first resistance, and the resistance value is a temperature. A second temperature-sensitive element exhibiting a negative temperature characteristic with respect to a change is connected between the second gate region and the second cathode region in parallel with the second resistor.

According to the present invention, by adopting such a manufacturing method, the resistance exhibits a negative temperature characteristic with respect to a temperature change in parallel with a conventional resistor between the gate region and the cathode region of the thyristor. The resistance between the gate and cathode regions can be increased at room temperature by connecting a temperature-sensitive element that reduces the resistance at high temperatures, improving the photosensitivity and lowering the resistance at high temperatures. The flow characteristics are improved.

Further, according to the method of manufacturing a light-triggered lateral bidirectional thyristor of the present invention, there is provided a semiconductor substrate of a first conductivity type, and a first anode region of a second conductivity type formed on a main surface of the semiconductor substrate. A first thyristor comprising a first gate region of the second conductivity type and a first cathode region of the first conductivity type formed in the first gate region; a semiconductor substrate of the first conductivity type; A second conductive type second anode region formed on the main surface of the substrate, a second conductive type second gate region, and a first conductive type second cathode region formed in the second gate region A second thyristor connected in anti-parallel to the first thyristor, a first resistor connecting the first gate region and the first cathode region, a second gate region and a second cathode region Optical trigger comprising a second resistor connecting the In literal type bidirectional thyristor, said first diode in which a plurality of serially connected first
A second diode connected in parallel with the first resistor between the gate region and the first cathode region, and a plurality of second diodes connected in series between the second gate region and the second cathode region. It may be connected in parallel with the second resistor.

According to the present invention, a plurality of serially connected diodes are connected between the gate region and the cathode region of the thyristor in parallel with the conventional resistor between the gate region and the cathode region of the thyristor. Since the resistance between the region and the cathode region can be increased, the photosensitivity is improved, and at high temperatures the forward voltage of the diode decreases,
The rise in potential between the gate and the cathode is reduced, and the commutation characteristics are improved.

Particularly, in this case, when the first and second diodes connected in series are manufactured on the same semiconductor substrate as the first and second thyristors in the same manufacturing process, the plurality of diodes are connected in series. By manufacturing the diode on the same semiconductor substrate as the thyristor in the same manufacturing process, the photosensitivity lateral bidirectional thyristor with improved photosensitivity at room temperature and improved commutation characteristics at high temperature can be manufactured at low cost. It can be realized even more easily.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings.

(Embodiment 1) FIG. 1 is a sectional view of a light-triggered lateral bidirectional thyristor according to an embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes an n-type semiconductor substrate;
Reference numerals 1 and 22 denote a pair of p-type anode regions formed on the main surface of the semiconductor substrate 1, respectively.
A pair of p-type gate regions formed on the main surface of the p-type gate regions, 41 and 42 are a pair of n-type cathode regions formed in the p-type gate regions 31 and 32, 51 and 52 are a pair of anode electrodes, respectively. 61 and 62 are a pair of gate electrodes, 71 and 72 are a pair of cathode electrodes, 81 and 82 are metal wirings, 9 is a silicon oxide film, R
1 is a resistor connecting the p-type gate region 31 and the n-type cathode region 41, R2 is a resistor connecting the p-type gate region 32 and the n-type cathode region 42, 101 is the p-type gate region 3
A resistance value connected in parallel with the resistor R1 between the first and n-type cathode regions 41 exhibits a negative temperature characteristic with respect to a temperature change, that is, a temperature-sensitive element having a low resistance at a high temperature. And a resistance value connected in parallel with the resistor R2 between the n-type cathode region 42 and the n-type cathode region 42 shows a negative temperature characteristic with respect to a temperature change.
1, T2 is an external connection terminal, and the first thyristor 100 is from the anode electrode 51, the p-type anode region 21, the n-type semiconductor substrate 1, the p-type gate region 31, the gate electrode 61, the n-type cathode region 41, and the cathode electrode 71. And the second thyristor 200 is an anode electrode 5
2, p-type anode region 22, n-type semiconductor substrate 1, p-type gate region 32, gate electrode 62, n-type cathode region 4
2, a lateral thyristor comprising a cathode electrode 72.

The operation of the thus-constructed embodiment at room temperature will be described. The external connection terminals T1, T2
Is applied with an AC voltage, but at some point T1 is positive and T
2 assumes that a negative voltage is applied. At this point, LE
When there is no light irradiation by D, the first thyristor 100
Both the second thyristors 200 are in a cutoff state, and T1,
There is no conduction between T2. Here, when light irradiation is performed by the LED, holes serving as minority carriers are generated in the n-type semiconductor substrate 1. The generated holes spread in the n-type semiconductor substrate 1 by diffusion, enter the p-type gate region 31, and reach the external terminal T2 through the resistor R1 and the temperature-sensitive element 101. At this time, a potential rise occurs due to the resistance R1 and the temperature-sensitive element 101, the pn junction between the p-type gate region 31 and the n-type cathode region 41 is forward-biased, and the first thyristor 100 becomes conductive. Here, the photosensitivity at room temperature is improved by increasing the value of the resistor R1. Next, considering the commutation characteristics at a high temperature, if T1 is a positive voltage and the first thyristor 100 is conducting, excessive holes are injected from the p-type anode region 21 into the n-type semiconductor substrate 1, Since the temperature is high, the mobility is large and the number of holes entering the p-type gate region 32 also increases. However, since the resistance value of the temperature-sensitive element 101 decreases at high temperature, the potential rise is small and the p-type gate region 32 and the n-type The pn junction of the cathode region 42 is not forward biased and the second thyristor 200
Does not conduct. That is, the commutation characteristics are improved.

(Embodiment 2) FIG. 2 is a sectional view of a light-triggered lateral bidirectional thyristor according to an embodiment of the present invention.

In FIG. 2, reference numeral 1 denotes an n-type semiconductor substrate;
Reference numerals 1 and 22 denote a pair of p-type anode regions formed on the main surface of the semiconductor substrate 1, respectively.
A pair of p-type gate regions formed on the main surface of the p-type gate regions, 41 and 42 are a pair of n-type cathode regions formed in the p-type gate regions 31 and 32, 51 and 52 are a pair of anode electrodes, respectively. 61 and 62 are a pair of gate electrodes, 71 and 72 are a pair of cathode electrodes, 81 and 82 are metal wirings, 9 is a silicon oxide film, R
1 is a resistor connecting the p-type gate region 31 and the n-type cathode region 41, R2 is a resistor connecting the p-type gate region 32 and the n-type cathode region 42, 201 is the p-type gate region 3
The resistance value connected in parallel with the resistor R1 between the first and n-type cathode regions 41 exhibits a negative temperature characteristic with respect to a temperature change, that is, a thermistor having a low resistance at high temperature. Between the cathode region 42 and the resistor R2
Thermistor whose resistance value connected in parallel shows a negative temperature characteristic with respect to temperature change, that is, thermistor which becomes low resistance at high temperature,
T1 and T2 are external connection terminals, and the first thyristor 100 is from the anode electrode 51, the p-type anode region 21, the n-type semiconductor substrate 1, the p-type gate region 31, the gate electrode 61, the n-type cathode region 41, and the cathode electrode 71. And the second thyristor 200 is an anode electrode 5
2, p-type anode region 22, n-type semiconductor substrate 1, p-type gate region 32, gate electrode 62, n-type cathode region 4
2, a lateral thyristor comprising a cathode electrode 72.

In the present embodiment configured as described above, since the configuration is the same as that of the first embodiment at room temperature, the light sensitivity is improved by increasing the resistance R1. Regarding the commutation characteristics at a high temperature, since a thermistor whose resistance value decreases at a high temperature is connected between the gate and the cathode, the potential rise during this period is small, and the second thyristor 200 does not conduct. That is, the commutation characteristics are improved.

(Embodiment 3) FIG. 3 is a sectional view of a light-triggered lateral bidirectional thyristor according to an embodiment of the present invention.

In FIG. 3, reference numeral 1 denotes an n-type semiconductor substrate;
Reference numerals 1 and 22 denote a pair of p-type anode regions formed on the main surface of the semiconductor substrate 1, respectively.
A pair of p-type gate regions formed on the main surface of the p-type gate regions, 41 and 42 are a pair of n-type cathode regions formed in the p-type gate regions 31 and 32, 51 and 52 are a pair of anode electrodes, respectively. 61 and 62 are a pair of gate electrodes, 71 and 72 are a pair of cathode electrodes, 81 and 82 are metal wirings, 9 is a silicon oxide film, R
1 is a resistor connecting the p-type gate region 31 and the n-type cathode region 41, R2 is a resistor connecting the p-type gate region 32 and the n-type cathode region 42, and 301 is a p-type gate region 3
A plurality of diodes are connected in series between the p-type gate region 31 and the n-type cathode region 41 in parallel with the resistor R1. T1, T2 are external connection terminals, the first thyristor 100 is an anode electrode 5
1, p-type anode region 21, n-type semiconductor substrate 1, p-type gate region 31, gate electrode 61, n-type cathode region 4
1, a lateral thyristor comprising a cathode electrode 71,
The second thyristor 200 includes an anode electrode 52, a p-type anode region 22, an n-type semiconductor substrate 1, and a p-type gate region 3.
2, a lateral thyristor including a gate electrode 62, an n-type cathode region 42, and a cathode electrode 72.

In this embodiment having such a configuration, since a plurality of diodes are connected in series between the gate and the cathode, the forward voltage VF of the diode at room temperature at room temperature is obtained.
The diode does not turn on until the number of applied voltages. Therefore, the value of the resistor R1 can be increased, and the light sensitivity is improved. Regarding the commutation characteristics at a high temperature, since the VF of the diode decreases at a high temperature, the rise in the potential between the gate and the cathode becomes small, and the second thyristor 200 does not conduct. That is, the commutation characteristics are improved.

(Embodiment 4) FIG. 4 is a sectional view of a light-triggered lateral bidirectional thyristor according to an embodiment of the present invention.

In FIG. 4, reference numeral 1 denotes an n-type semiconductor substrate;
Reference numerals 1 and 22 denote a pair of p-type anode regions formed on the main surface of the semiconductor substrate 1, respectively.
A pair of p-type gate regions formed on the main surface of the p-type gate regions, 41 and 42 are a pair of n-type cathode regions formed in the p-type gate regions 31 and 32, 51 and 52 are a pair of anode electrodes, respectively. 61 and 62 are a pair of gate electrodes, 71 and 72 are a pair of cathode electrodes, 81 and 82 are metal wirings, 9 is a silicon oxide film, R
1 is a resistor connecting the p-type gate region 31 and the n-type cathode region 41, R2 is a resistor connecting the p-type gate region 32 and the n-type cathode region 42, and 401 is a p-type gate region 3
A plurality of diodes are connected in series between the first and n-type cathode regions 41 in parallel with the resistor R1. The p-type anode of the diode is formed with the same diffusion as the p-type anode and the p-type gate of the thyristor. Type cathode is formed by the same diffusion as the n-type cathode of the thyristor,
Between the gate region 31 and the n-type cathode region 41
A plurality of diodes connected in series in parallel with 1; the p-type anode of the diode is the p-type anode of the thyristor;
The n-type cathode of the diode is formed with the same diffusion as the n-type cathode of the thyristor, T1 and T2 are external connection terminals, the first thyristor 100 is the anode electrode 51, and the p-type Anode region 21,
n-type semiconductor substrate 1, p-type gate region 31, gate electrode 6
A lateral thyristor comprising a 1, n-type cathode region 41 and a cathode electrode 71, and a second thyristor 200 comprises an anode electrode 52, a p-type anode region 22, an n-type semiconductor substrate 1, a p-type gate region 32, a gate electrode 62, n This is a lateral thyristor comprising a mold cathode region 42 and a cathode electrode 72.

In this embodiment constructed as described above, since a plurality of diodes are connected in series between the gate and the cathode, the forward voltage VF of the diode at room temperature at room temperature is obtained.
The diode does not turn on until the number of applied voltages. Therefore, the value of the resistor R1 can be increased, and the light sensitivity is improved. Regarding the commutation characteristics at a high temperature, since the VF of the diode decreases at a high temperature, the rise in the potential between the gate and the cathode becomes small, and the second thyristor 200 does not conduct. That is, the commutation characteristics are improved. Further, since this diode can be formed in the same step as the step of forming the thyristor, it can be manufactured at a low cost without increasing an extra step.

[0038]

According to the photo-triggered lateral bidirectional thyristor according to the first aspect of the present invention, the resistance exhibits a negative temperature characteristic with respect to a temperature change in parallel with the resistance between the gate and the cathode of the thyristor. Since a temperature-sensitive element that reduces resistance is connected, the light sensitivity can be adjusted by the resistance value at room temperature. Therefore, if this resistance is set high, the light sensitivity is improved, and at high temperatures, the sensitivity is improved. The temperature element has a low resistance, resulting in improved commutation characteristics.

According to the photo-triggered lateral bidirectional thyristor according to the second aspect of the present invention, in addition to the first aspect, the resistance in parallel with the resistance between the gate and the cathode of the thyristor is negative with respect to a temperature change. Because it connects a thermistor that shows low temperature resistance at high temperature,
At room temperature, the light sensitivity can be reliably adjusted by the value of the resistance.If this resistance is set high, the light sensitivity will surely improve, and at high temperatures, the thermistor will surely have low resistance. In addition, the commutation characteristics are more reliably improved.

According to the photo-triggered lateral bidirectional thyristor according to the third aspect of the present invention, a plurality of diodes are connected in series in parallel with the resistance between the gate and the cathode of the thyristor. The diode does not turn on until the voltage equal to the forward voltage VF multiplied by
Therefore, if the value of the resistor is set high, the light sensitivity is improved.
Regarding the commutation characteristics at a high temperature, since the VF of the diode decreases at a high temperature, the rise in the potential between the gate and the cathode becomes small, and the thyristor does not conduct, so that the commutation characteristics are improved. .

According to the method for manufacturing a light-triggered lateral bidirectional thyristor according to claim 4 of the present invention, the resistance exhibits a negative temperature characteristic with respect to a temperature change in parallel with the resistance between the gate and the cathode of the thyristor. Since a temperature-sensitive element that has a low resistance at high temperatures is connected, the light sensitivity can be adjusted by the resistance value at room temperature, so if this resistance is set high, the light sensitivity is improved, and at high temperatures, The temperature-sensitive element has low resistance, resulting in improved commutation characteristics.

According to the method for manufacturing a light-triggered lateral bidirectional thyristor according to claim 5 of the present invention, a plurality of diodes are connected in series in parallel with the resistance between the gate and the cathode of the thyristor. The diode does not turn on until the voltage equal to the number of times the forward voltage VF of the diode is multiplied, so that if the value of the resistor is set high, the light sensitivity is improved. Regarding the commutation characteristics at a high temperature, since the VF of the diode decreases at a high temperature, the rise in the potential between the gate and the cathode decreases, and the thyristor does not conduct, so that the commutation characteristics are improved. .

According to the method of manufacturing a light-triggered lateral bidirectional thyristor according to claim 6 of the present invention, in addition to the structure of claim 5, a plurality of diodes are connected in series with the resistance between the gate and the cathode of the thyristor. At room temperature, the diode does not turn on until the voltage equal to the number of forward voltages VF of the diode at room temperature multiplied by the number thereof. Therefore, if the resistance value is set to a high value, the light sensitivity is surely improved. As for the commutation characteristics at high temperatures, since the VF of the diode decreases at high temperatures, the rise in the potential between the gate and the cathode is small, and the thyristor does not conduct, so that the commutation characteristics are surely improved. Becomes Further, since this diode can be formed in the same step as the step of forming the thyristor, it can be manufactured at a low cost without adding an extra step.

[Brief description of the drawings]

FIG. 1 is a sectional view of a first embodiment of a light-triggered lateral bidirectional thyristor of the present invention.

FIG. 2 is a sectional view of a second embodiment of the light-triggered lateral bidirectional thyristor of the present invention.

FIG. 3 is a sectional view of a third embodiment of the light-triggered lateral bidirectional thyristor of the present invention.

FIG. 4 is a sectional view of a fourth embodiment of the light-triggered lateral bidirectional thyristor of the present invention.

FIG. 5 is a cross-sectional view of a conventional light-triggered lateral bidirectional thyristor.

[Explanation of symbols]

1. n-type semiconductor substrate 21, 22,. p-type anode regions 31, 32. p-type gate regions 41, 42. n-type cathode regions 51, 52. Anode electrode 61, 62. Gate electrode 71, 72. Cathode electrode 81, 82. Metal wiring 9. Silicon oxide film 100. First thyristors 101, 102. Thermosensitive element 200. Second thyristor 201, 202. Thermistors 301, 302. A plurality of diodes 401, 402. Diodes formed on the same substrate as the thyristor R1, R2. Resistance T1, T2. External connection terminal

Claims (6)

[Claims] 1. A semiconductor substrate of a first conductivity type, a first anode region of a second conductivity type, a first gate region of a second conductivity type, and a first gate formed on a main surface of the semiconductor substrate. A first thyristor comprising a first cathode region of the first conductivity type formed in the region, a semiconductor substrate of the first conductivity type,
A second anode region of the second conductivity type formed on the main surface of the semiconductor substrate, a second gate region of the second conductivity type, and a second gate region of the first conductivity type formed in the second gate region. A second thyristor composed of a cathode region and connected in anti-parallel with the first thyristor; a first resistor connecting the first gate region and the first cathode region; a second thyristor connected to the first thyristor; In a photo-triggered lateral bidirectional thyristor comprising a second resistor connecting a cathode region, a first temperature-sensitive element having a resistance value exhibiting a negative temperature characteristic with respect to a temperature change is provided by the first gate region and the first temperature-sensitive element. Between the cathode regions of the first
A second temperature-sensitive element having a resistance value exhibiting a negative temperature characteristic with respect to a temperature change and being connected in parallel with the second resistor between the second gate region and the second cathode region. A light-triggered lateral bidirectional thyristor, characterized in that it is connected to a thyristor. 2. The light-triggered lateral bidirectional thyristor according to claim 1, wherein both the first temperature-sensitive element and the second temperature-sensitive element are thermistors. 3. A semiconductor substrate of a first conductivity type, a first anode region of a second conductivity type, a first gate region of a second conductivity type, and a first gate formed on a main surface of the semiconductor substrate. A first thyristor comprising a first cathode region of the first conductivity type formed in the region, a semiconductor substrate of the first conductivity type,
A second anode region of the second conductivity type formed on the main surface of the semiconductor substrate, a second gate region of the second conductivity type, and a second gate region of the first conductivity type formed in the second gate region. A second thyristor composed of a cathode region and connected in anti-parallel with the first thyristor; a first resistor connecting the first gate region and the first cathode region; a second thyristor connected to the first thyristor; In a photo-triggered lateral bidirectional thyristor comprising a second resistor connecting a cathode region, a first diode connected in series is connected between the first gate region and the first cathode region. And a plurality of second diodes connected in parallel with each other in series and connected in series with the second resistor between the second gate region and the second cathode region. Optical trigger lateral type bidirectional Irisuta. 4. A semiconductor substrate of a first conductivity type, a first anode region of a second conductivity type, a first gate region of a second conductivity type, and a first gate formed on a main surface of the semiconductor substrate. A first thyristor comprising a first cathode region of the first conductivity type formed in the region, a semiconductor substrate of the first conductivity type,
A second anode region of the second conductivity type formed on the main surface of the semiconductor substrate, a second gate region of the second conductivity type, and a second gate region of the first conductivity type formed in the second gate region. A second thyristor composed of a cathode region and connected in anti-parallel with the first thyristor; a first resistor connecting the first gate region and the first cathode region; a second thyristor connected to the first thyristor; In a photo-triggered lateral bidirectional thyristor comprising a second resistor connecting a cathode region, a first temperature-sensitive element having a resistance value exhibiting a negative temperature characteristic with respect to a temperature change is provided by the first gate region and the first temperature-sensitive element. Between the cathode regions of the first
And a second temperature-sensitive element having a resistance value exhibiting a negative temperature characteristic with respect to a temperature change is connected in parallel with the second resistor between the second gate region and the second cathode region. A method for manufacturing a light-triggered lateral bidirectional thyristor, comprising: 5. A semiconductor substrate of a first conductivity type, a first anode region of a second conductivity type, a first gate region of a second conductivity type, and a first gate formed on a main surface of the semiconductor substrate. A first thyristor comprising a first cathode region of the first conductivity type formed in the region, a semiconductor substrate of the first conductivity type,
A second anode region of the second conductivity type formed on the main surface of the semiconductor substrate, a second gate region of the second conductivity type, and a second gate region of the first conductivity type formed in the second gate region. A second thyristor composed of a cathode region and connected in anti-parallel with the first thyristor; a first resistor connecting the first gate region and the first cathode region; a second thyristor connected to the first thyristor; In a photo-triggered lateral bidirectional thyristor comprising a second resistor connecting a cathode region, a first diode connected in series is connected between the first gate region and the first cathode region. A second diode connected in parallel with the resistor of
A method for manufacturing a light-triggered lateral bidirectional thyristor, comprising: connecting a second resistor in parallel between the gate region and the second cathode region. 6. The semiconductor device according to claim 5, wherein the first and second diodes connected in series are manufactured on the same semiconductor substrate as the first and second thyristors in the same manufacturing process. A method for manufacturing a light-triggered lateral bidirectional thyristor.