JP3388705B2 - Semiconductor device and solid state relay for ignition - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device, and more particularly to a thyristor element used in a commercial frequency line or the like, a bidirectional thyristor element, and a solid state relay for ignition using the semiconductor device.

[0002]

2. Description of the Related Art As is well known, a bidirectional thyristor is formed on, for example, an N-type silicon substrate, and is turned on / off by a gate trigger signal given by light irradiation or current. This type of bidirectional thyristor is widely used as a so-called ignition SSR (solid state relay).

FIG. 11 is a plan sectional view schematically showing a conventional bidirectional phototriac. FIG. 12 is a sectional view taken along the line DD ′ in FIG.

11 and 12, each P-type anode diffusion region 102 is formed on the surface of an N-type silicon substrate 101.
And each P gate diffusion region 103 facing these P type anode diffusion regions 102 are provided.

In each P gate diffusion region 103, each N type cathode diffusion region 104 is formed.

Each P gate diffusion region 103 and each P type anode diffusion region 102 are connected via each gate resistor 105.

Each P-type anode region 102, N-type silicon substrate 101, each P-gate diffusion region 103, and each N-type cathode diffusion region 104 form a lateral PNPN structure and have two reverse gate resistance regions. A blocking photothyristor (bidirectional photothyristor 121) is formed.

The N-type silicon substrate 101 generally has an impurity concentration of 10 ¹³ to 10 ¹⁵ atoms / cm ³ . A channel stopper region 106 is provided around the portion where the bidirectional photothyristor 121 is formed. An N-type diffusion layer 107 is provided on the back surface of the N-type silicon substrate 101. The channel stopper region 106 and the N-type diffusion layer 107 on the back surface are high-concentration N-type diffusion layers.

An Al wiring 112 is formed on the surface of the N-type silicon substrate 101 for electrical connection, and a SiO ₂ film 109 and an oxygen-doped semi-absorptive film 110 are formed on a portion where electrical insulation is required. Forming a passivation film.

In the bidirectional photothyristor 121, each P gate light receiving portion 111 for receiving an optical signal is formed. In these P gate light receiving portions 111, the Al wiring 112 is removed and opened.

FIG. 13 shows an equivalent circuit of the bidirectional photothyristor 121 shown in FIGS. 11 and 12.

In FIG. 13, two photothyristors CH1 and CH2 are formed in parallel with each other. The bidirectional photothyristor 121 operates as a light control type bidirectional thyristor by injecting the light from the light emitting diode 123 into the surface (each P gate light receiving portion 111) of the bidirectional photothyristor 121. For SSR)
Used as.

FIG. 14 shows a basic circuit configuration in which the light control type bidirectional photothyristor 121 is applied to a firing SSR. The ignition SSR 122 includes a bidirectional photothyristor 121 and a light emitting diode 123. A main triac 124 and a snubber circuit 125 are connected to the output side of the ignition SSR 122, and a load 126, an AC power supply 127 and a switch 128 are connected to the snubber circuit 125.

The waveform of the output voltage of the AC power supply 127 is shown in FIG.
It is shown by a solid line 131 in 5 (a). When the switch 128 is turned on, the light emitting diode 123 is caused to emit light at an appropriate cycle, and the bidirectional photothyristor 121 is turned on each time the light emitting diode 123 emits light, and accordingly, the main triac 124 is also turned on. Become, load 126
, A current i indicated by a dotted line 132 in FIG.
The load 126 consumes electric power indicated by diagonal lines. At this time, the light emitting diode 123 has a structure shown in FIG.
An input control current I _{F of} about 20 mA shown in (b) flows.

[0015]

[Problems to be Solved by the Invention] The above conventional SS for ignition.
In R, a light emitting diode 123 is used to trigger the bidirectional photothyristor 121. In addition, other types of conventional SSRs for ignition also require a signal current to trigger the bidirectional photothyristor. Therefore, it is necessary to always operate the circuit that controls the light or the trigger current by some method.
Energy was consumed even during the standby time.

For example, in the circuit shown in FIG. 14, an input control current I _{F of} about 20 mA is periodically required during operation. In recent years environmental issues, reducing the power consumption of manufacturers is an important task.

Therefore, the present invention has been made in view of the above conventional problems, and an object of the present invention is to provide a semiconductor device and a solid state relay for ignition, which can reduce power consumption.

[0018]

In order to solve the above-mentioned conventional problems, the semiconductor device of the present invention is a semiconductor of the first conductivity type.
A substrate and a second conductivity type first substrate provided on the surface of the semiconductor substrate.
A first anode diffusion region and a second anode diffusion region;
It is provided on the surface of the semiconductor substrate facing the first anode diffusion region.
The first gate diffusion region of the second conductivity type, and the second anode
Provided on the surface of the semiconductor substrate facing the battery diffusion region
A second gate diffusion region of a second conductivity type and the first gate diffusion region
First conductivity type first cathode diffusion region formed in the castle
Of the first conductivity type formed in the second gate diffusion region
A second cathode diffusion region, a first anode diffusion region and a first anode diffusion region;
A first gate resistor connecting the first gate diffusion region and the first gate resistor;
2 Connect the anode diffusion region and the second gate diffusion region
Having a second gate resistance, the semiconductor substrate, and anode diffusion
Area, cathode diffusion area and gate diffusion area
In a semiconductor device forming a directional thyristor, the semiconductor
On the surface of the body substrate, one end of the semiconductor substrate is formed by the first wiring.
To the first gate diffusion region of the second conductivity type, the other end of which is connected to
Third resistor for changing voltage between connected thyristor terminals
And one end is connected to the semiconductor substrate by the second wiring.
A terminal whose end is connected to the second gate diffusion region of the second conductivity type.
And a fourth resistor for changing the voltage between the iris terminals .

In one embodiment, the resistance value of the third and fourth resistors is 0.5-100 MΩ.

In one embodiment, the resistance value of the third and fourth resistors is 1 to 30 MΩ.

[0021] In one embodiment,Third and fourthresistance
Is a doped silicon film formed on the semiconductor substrate.
Is.

In one embodiment, the third and fourth resistors are external fixed resistors.

In one embodiment, the bidirectional thyristor is responsive to a gate current applied to each gate of the bidirectional thyristor.

In one embodiment, the bidirectional thyristor is responsive to light applied to each gate of the bidirectional thyristor.

The solid-state relay for ignition according to the present invention has the above semiconductor device connected to an AC power source,
The semiconductor device is turned on and off, and in response thereto, the power of the power supply is supplied to the load.

Further, the semiconductor device of the present invention has a plurality of PNs.
A semiconductor device having a unidirectional negative thyristor including a junction formed on a semiconductor substrate, wherein a gate of the unidirectional negative thyristor is connected to the semiconductor substrate via a resistor. Immediately
The semiconductor device of the present invention is a semiconductor substrate of the first conductivity type.
And a second conductivity type anod provided on the surface of the semiconductor substrate.
And a semiconductor facing the anode diffusion region.
A second conductivity type gate diffusion region provided on the substrate surface;
A cathode diffusion region formed in the gate diffusion region,
A gate connecting the anode diffusion region and the gate diffusion region.
Resistance of the semiconductor substrate, the anode diffusion region,
Thyristor with sword diffusion region and gate diffusion region
Forming a semiconductor device on the surface of the semiconductor substrate
, One end is connected to the semiconductor substrate by wiring and the other end is
Thyristor terminal connected to the two conductivity type gate diffusion region
A resistor is provided for changing the voltage.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a plan view showing an embodiment of the semiconductor device of the present invention. 2 is a sectional view taken along the line AA ′ in FIG. 1, FIG. 3 is a sectional view taken along the line BB ′ in FIG. 1, and FIG. 4 is a sectional view taken along the line CC ′ in FIG. It is a figure.

The semiconductor device of this embodiment is a lateral bidirectional thyristor with a PNPN structure, like the conventional semiconductor device shown in FIGS.

In the semiconductor device of this embodiment, the doped polysilicon films 15 and 15 are newly provided with a resistance of about 20 MΩ, and the doped polysilicon films 15 and 1 are provided.
5, the N-type silicon substrate 1 and the P gate diffusion regions 3 and 3 are connected to each other.

1 to 4, each P-type anode diffusion region 2 and each P-gate diffusion region 3 facing each anode diffusion region 2 are provided on the surface of the N-type silicon substrate 1. .

In each P gate diffusion region 3, each N type cathode diffusion region 4 is formed.

Each P gate diffusion region 3 and each P type anode diffusion region 2 are connected via a respective gate resistor 5.

Each P-type anode region 2, N-type silicon substrate 1, each P-gate diffusion region 3, and each N-type cathode diffusion region 4 form a lateral PNPN structure and have two reverse gate resistance regions. A blocking thyristor (bidirectional thyristor 21) is formed.

The N-type silicon substrate 1 generally has an impurity concentration of 10 ¹³ to 10 ¹⁵ atoms / cm ³ . A channel stopper region 6 is provided around the portion where the bidirectional thyristor is formed. The channel stopper region 6 has a high concentration of N-type diffusion.

An Al wiring 12 is formed on the surface of the N-type silicon substrate 1 for electrical connection, and the SiO ₂ film 9 and the oxygen-doped semi-absorptive film 10 are passivated in a portion where electrical insulation is required. Forming a film.

The doped polysilicon film 15 is formed by a vapor phase epitaxy method before the Al vapor deposition step, and then is controlled to a desired resistance value Rx by an ion implantation method using boron as an atom.

As is apparent from FIG. 3, the upper end 15a of the doped polysilicon film 15 is connected to the Al wiring 12,
It is connected to the N-type silicon substrate 1 through this Al wiring 12. Further, as is apparent from FIG. 4, the lower end 15b of the doped polysilicon film 15 is covered with the Al wiring 12 and is connected to the P gate diffusion region 3 through the contact hole 9a of the SiO ₂ film 9.

FIG. 5 shows an equivalent circuit of the bidirectional thyristor 21 which is the semiconductor device of this embodiment.

In FIG. 5, two thyristors CH1,
CH2 is formed by connecting in parallel with each other. Each terminal 21
When an AC voltage is applied between a and 21b, each thyristor C
Hl and CH2 are alternately turned on. That is, in the thyristor CH1, a current flows between the terminal 21a and the N-type silicon substrate 1 through the gate resistor 5 and the doped polysilicon film 15, and when the gate current of the transistor T2 exceeds the trigger current value, each transistor is turned on. T2 and T3 are turned on, and the thyristor CH1 is turned on. Similarly, also in the thyristor CH2, when the gate current of the transistor T4 exceeds the trigger current value, each transistor T4
1, T4 is turned on, and the thyristor CH2 is turned on.

Therefore, the bidirectional thyristor 2 of this embodiment is used.
1 is a self-trigger type that does not require a trigger current from the outside and forms the trigger current internally.

In each of the thyristors CH1 and CH2, by changing the resistance value R _X of the doped polysilicon film 15, the voltage value between the terminals 21a and 21b when the thyristors CH1 and CH2 are turned on. Can be changed.

The semiconductor device of this embodiment does not have an N-type diffusion layer on the back surface of the N-type silicon substrate 1 as compared with the conventional semiconductor device. As a result, the carrier lifetime in the bulk is reduced, and each thyristor CH1,
The so-called commutation characteristic when CH2 is switched alternately is improved.

FIG. 6 shows the bidirectional thyristor 2 of this embodiment.
1 shows a self-operation type SSR circuit in which 1 is applied as an SSR for ignition. In this self-operating SSR circuit, the ignition SSR is composed of only the bidirectional thyristor 21. A main triac 24 and a snubber circuit 25 are connected to the output side of the bidirectional thyristor 21.
A load 26, an AC power supply 27, and a switch 28 are connected to the.

The waveform of the output voltage of the AC power supply 27 is shown by the solid line 31 in FIG. When the switch 28 is turned on, the output voltage from the AC power source 27 is applied between the terminals 21a and 21b, and as described above, the thyristors CH1 and CH2 of the bidirectional thyristor 21 are alternately turned on. As a result, the current i shown by the dotted line 32 in FIG. 7 flows through the load 26, and the electric power shown by the diagonal lines is consumed in the load 26.

As described above, each thyristor CH1, C
In either case of H2, the doped polysilicon film 15
By changing the resistance value R _X of each thyristor C
The voltage value between the terminals 21a and 21b at which H1 and CH2 are turned on can be changed. Along with this, the timing of turning on each of the thyristors CH1 and CH2 is changed, so that the load 2 indicated by the shaded portion in FIG.
The power consumption of 6 is changed. Therefore, the power consumption of the load 26 can be adjusted by changing the resistance value R _X of the doped polysilicon film 15.

FIG. 8 is a graph showing the ratio of the power consumption of the load 26 to the resistance value R _X in the bidirectional thyristor 21. As is clear from this graph, the power consumption of the load 26 changes according to the resistance value R _X. Considering variations in the characteristics of the bidirectional thyristor 21, it is necessary to set the resistance value R _X in the range of 0.5 to 100 MΩ, and in order to maintain the preferable power consumption of the load 26, the resistance value R _X is set to 1 It must be set within the range of 30 MΩ.

Resistance value R _{X of the} doped polysilicon film 15
Are set when the semiconductor device shown in FIGS. 1 to 4 which is the bidirectional thyristor 21 is manufactured. in this case,
The resistance can be integrated in the semiconductor device, and there is almost no increase in cost.

Alternatively, instead of using the doped polysilicon film 15, each wiring is drawn out from a portion where both ends of the doped polysilicon film 15 are connected,
A single resistor may be externally attached to these wirings. In this case, the resistance value R _X can be easily changed by appropriately replacing the external resistance. If a variable resistor is used as the external resistor, the resistance value R _X can be freely changed and the phase of the power consumption of the load 26 can be controlled.

FIG. 9 shows the bidirectional thyristor 2 of this embodiment.
1 shows a self-controlled SSR circuit in which 1 is applied as an SSR for ignition. In this self-controlled SSR circuit, when the switch 41 is turned on, the AC voltage output from the AC power supply 42 and shown by the solid line in FIG.
1 and the rectifier circuit 43. At this time, the current i shown by the dotted line in FIG. 10A flows from the bidirectional thyristor 21 to the rectifier circuit 43, and DC power is supplied from the rectifier circuit 43 to the load 44.

The standby circuit 45 detects the input voltage of the rectifier circuit 43 and supplies a gate current I _G as shown in FIG. 10B to the gates of the transistors T2 and T4 of the bidirectional thyristor 21 as needed. Then, the timing at which the thyristors CH1 and CH2 are turned on is changed accordingly.
As a result, the electric power supplied from the bidirectional thyristor 21 to the rectifier circuit 45 is changed as shown by the hatched portion in FIG.

This self-control type SSR circuit can first act as a self-operation type phase control device, and after operating once, receives a signal from the standby circuit,
Phase (power) control can be performed in several steps. Therefore, waste of energy during standby is eliminated, which is very effective for energy saving.

Although the bidirectional thyristor 21 is illustrated in this embodiment, each thyristor CH in FIG.
A self-triggered unidirectional thyristor can be provided by extracting only one of CH1 and CH2.

Further, if each P-gate light receiving portion 11 shown in FIG. 2 is opened, it is possible to provide a bidirectional thyristor 21 which is a self-trigger type and which is triggered by an optical input.

[0055]

As described above, the semiconductor device of the present invention is a self-trigger type thyristor and does not require a trigger current during standby, so that energy consumption can be reduced. Further, since the light emitting diode is unnecessary, the assembly cost can be reduced, the reliability is not deteriorated due to the deterioration of the light emission output of the light emitting diode, and the life can be improved.

The SS to which the semiconductor device of the present invention is applied
In the R circuit, the power of the load can be easily changed by adjusting the gate current of the semiconductor device.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a semiconductor device of the present invention.

FIG. 2 is a cross-sectional view taken along the line A-A ′ in FIG.

3 is a cross-sectional view taken along the line B-B 'in FIG.

FIG. 4 is a cross-sectional view taken along the line C-C ′ in FIG.

FIG. 5 is an equivalent circuit diagram showing a bidirectional thyristor which is the semiconductor device of the present embodiment.

FIG. 6 is a diagram showing a bidirectional thyristor of the present embodiment, which has an SSR for ignition
It is a block diagram showing a self-operation type SSR circuit applied as.

7 is a diagram showing an output waveform of the AC power supply and a current waveform of a bidirectional thyristor in FIG.

FIG. 8 is a graph showing a ratio of load power consumption to resistance value R _X in the bidirectional thyristor of the present embodiment.

FIG. 9 is an SSR for ignition of the bidirectional thyristor of this embodiment.
FIG. 3 is a block diagram showing a self-controlling SSR circuit applied as above.

10A is a diagram showing the output waveform of the AC power supply and the current waveform of the bidirectional thyristor in FIG. 9, and FIG.
FIG. 6 is a diagram showing a trigger current waveform of a bidirectional thyristor.

FIG. 11 is a plan view schematically showing a conventional bidirectional phototriac.

12 is a cross-sectional view taken along the line DD ′ in FIG.

13 is an equivalent circuit showing the bidirectional photothyristor shown in FIGS. 11 and 12. FIG.

FIG. 14 is a block diagram showing a basic circuit configuration in which the bidirectional photothyristor shown in FIGS. 11 and 12 is applied to a firing SSR.

15A is a diagram showing the output waveform of the AC power supply and the current waveform of the bidirectional thyristor in FIG. 14, and FIG.
FIG. 4 is a diagram showing an input control current waveform of a light emitting diode.

[Explanation of symbols]

1 N type silicon substrate 2 Anode diffusion area 3 P gate diffusion region 4 N-type cathode diffusion region 5 Gate resistance 6 Channel stopper area 15 Doped polysilicon film 21 Bidirectional thyristor

Continuation of front page (56) Reference JP-A-3-155637 (JP, A) JP-A-6-204464 (JP, A) JP-A-5-36977 (JP, A) JP-A-64-49265 (JP , A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01L 29/74

Claims (9)

(57) [Claims] 1. A semiconductor substrate of the first conductivity type and the semiconductor substrate.
Second conductivity type first anode diffusion region provided on the plate surface
And a second anode diffusion region and a surface of the semiconductor substrate facing the first anode diffusion region.
The second conductive type first gate diffusion region provided and the second gate diffusion region
Provided on the surface of the semiconductor substrate facing the node diffusion region
A second gate diffusion region of a second conductivity type and a first conductivity type first gate formed in the first gate diffusion region.
Formed in the cathode diffusion region and the second gate diffusion region.
A second cathode diffusion region of the first conductivity type connected to the first anode diffusion region and the first gate diffusion region.
The first gate resistance, the second anode diffusion region and the second
A second gate resistor connecting to the gate diffusion region, the semiconductor substrate, the anode diffusion region, the cathode diffusion region, and
And a gate diffusion region form a bidirectional thyristor
In the semiconductor device, one end is connected to the semiconductor substrate surface by the first wiring.
The first gate diffusion connected to the body substrate and having the other end of the second conductivity type
The third for changing the voltage between the thyristor terminals connected to the area
One end is connected to the semiconductor substrate by the resistor and the second wiring.
And the other end is connected to the second gate diffusion region of the second conductivity type.
And a fourth resistor for changing the voltage between the thyristor terminals . 2. The resistance values of the third and fourth resistors are:
The semiconductor device according to claim 1, wherein the semiconductor device has a resistance of 0.5 to 100 MΩ. 3. The resistance values of the third and fourth resistors are:
The semiconductor device according to claim 1, wherein the semiconductor device has a resistance of 1 to 30 MΩ. 4. The semiconductor device according to claim 1, wherein the third and fourth resistors are doped silicon films formed on the semiconductor substrate. 5. The semiconductor device according to claim 1, wherein the third and fourth resistors are external fixed resistors. 6. The semiconductor device according to claim 1, wherein the bidirectional thyristor operates in response to a gate current applied to each gate of the bidirectional thyristor. 7. The semiconductor device according to claim 1, wherein the bidirectional thyristor operates in response to light applied to each gate of the bidirectional thyristor. 8. connected to an AC power source of a semiconductor device according to any one of claims 1 to 7, wherein the semiconductor device is turned on and off, and supplies ignition load power of the response power thereto Solid-state relay for. 9. A semiconductor substrate of the first conductivity type and the semiconductor substrate.
A second conductivity type anode diffusion region provided on the plate surface;
Provided on the surface of the semiconductor substrate facing the anode diffusion region
A gate diffusion region of the second conductivity type, a cathode diffusion region formed in the gate diffusion region, and a gate connecting the anode diffusion region and the gate diffusion region.
Of the semiconductor substrate, the anode diffusion region, and the cathode diffusion region.
And a semiconductor forming a thyristor with a gate diffusion region
In the device, one end of the semiconductor substrate is connected to the semiconductor substrate surface by wiring.
And the other end is connected to the second conductivity type gate diffusion region.
A semiconductor device with a resistor for changing the voltage between the thyristor terminals .