JPH0758326A - Semiconductor device with sensor element - Google Patents

Abstract

PURPOSE:To surely detect on-voltage at abnormal time by making the electrode, conduction-contacted to an emitter semiconductor region, contain the first conduction type high concentration region which partially causes short circuit at a base semiconductor region. CONSTITUTION:At a sensor cell part CS, a partial n<++>-type anode short region 30 is formed on the main surface side within a buffer region 14a. At the anode short region 30, a drift region 13a is, through a diffusion resistor rx of the buffer region 14a, connected to a collector electrode, and a collector region (emitter of transistor) is partially short-circuited. With this, since the sensor cell part CS shows step-like current waveform at abnormal time such as gate voltage drop and load short-circuit, its step width is available as detection margin, so, even if there is irregularity in element characteristics due to irregularity in manufacture process condition, detection error is absorbed its detection margin. Therefore, abnormality detection with high precision is realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device with a sensor element attached with a sensor semiconductor structure for detecting an on-voltage (operating voltage) of a main power switching element,
In particular, it relates to improvements in its sensor semiconductor structure.

[0002]

2. Description of the Related Art In a switching circuit using a power element as a switching element, an abnormality in a control circuit section for driving the power element or a load short-circuit abnormality is instantly detected as a change in ON voltage, and the power element is quickly shut off ( In order to turn off (off state), the chip (substrate) on which the power element is built has a microscale compared to the built-in scale (occupied area) of the power element, and has the same structure as the element structure of the power element. A semiconductor device with a sensor element in which the sensor element part (sensor semiconductor structure) is additionally formed is used.
FIG. 10 shows a lateral IGBT (conductivity modulation type M with a sensor element).
An example of a switching circuit using an OSFET and an insulated gate bipolar transistor will be shown. In this switching circuit, the lateral IGBT 2 with a sensor element is turned on / off (opened / closed) by the gate control signal from the gate control circuit 1, and, for example, the inductance load L is driven. As shown in the equivalent circuit of FIG. 11, the lateral IGBT 2 with a sensor element is composed of a main IGBT unit 2A and a sensor IGBT unit 2a connected in parallel. This main IGBT
The part 2A includes a pnp bipolar transistor Q _{pn p} having an emitter region connected to the collector terminal (anode terminal) C (A) of the IGBT, and the collector region of the transistor and the emitter terminal (cathode terminal) E of the IGBT.
An n-channel type M for injecting majority carriers for electrically connecting and disconnecting a collector resistance R connected between (K) and the emitter terminal E and the base region of the bipolar transistor Q _pnp.
OSFET (insulated gate field effect transistor) F _n
It consists of and. In addition, the sensor IGBT unit 2a
Also, the collector terminal (anode terminal) C of the IGBT
A pnp-type bipolar transistor q _pnp having an emitter region connected to (A), and a collector resistance r connected between the collector region of the transistor and the sensor emitter terminal (sensor cathode terminal) E _S (K _S ) of the IGBT.
And a n-channel MOSFET (f _n ) for injecting majority carriers for electrically connecting and disconnecting the sensor emitter terminal E _S and the base region of the bipolar transistor q _pnp . Therefore, when applying a high potential to the gate terminal _{G, MOSFET (F n, f} n) is turned both turned on, the emitter terminal E, majority carriers from E _S (electrons) pnp bipolar transistor Q _pnp, q _pnp Is injected into the n-type base region and its conductivity is modulated, whereby the pnp-type bipolar transistors Q _{pn p} and q _pnp are turned on, and a large current capacity current flows through the collector resistors R and r. The element IGBT scale of the sensor IGBT section 2a is formed much smaller than that of the main IGBT section 2A, and the current capacity of the sensor IGBT section 2a is the main I
This is very small compared to that of the GBT portion 2A.
Further, the semiconductor structure of the sensor IGBT part 2a is equal to that of the main IGBT part 2A, and therefore, as shown in FIG.
The characteristic of the collector current I _c with respect to the collector-emitter voltage V _CE of the sensor IGBT section 2a also has a similar shape to the characteristic of the main IGBT section 2A.

The switching circuit shown in FIG. 10 has a detection circuit 3, and the sensor emitter terminal E _{S is set} so that the collector current (substantially the same as the emitter current) of the sensor IGBT section 2a becomes substantially zero. Between the main IGBT unit 2A and the emitter terminal E of the main IGBT unit 2A
_S (emitter follower resistor) is connected. Therefore,
The output impedance (ON resistance) of the sensor IGBT part 2a is substantially zero, and the potential of the sensor emitter terminal E _S of the sensor IGBT part 2a is substantially equal to the potential of the collector terminal C. Here, when the logic amplitude of the gate control signal from the gate control circuit 1 is normal, for example, the gate voltage V shown in FIG.
_G1 and the collector current (carrying current) in the ON state is I ₁
Then, V _CE between collector-emitter voltage in ON state
(ON voltage V _ON ) is V ₁ , but if an abnormality occurs in the gate control circuit 1 and the logic amplitude of the gate control signal is reduced to, for example, the gate voltage V _G3 shown in FIG. Due to mutual induction of the load L, the collector current I _{1 of the} same value still tries to flow in the IGBT,
The collector-emitter voltage V _CE of the main IGBT portion 2A rapidly rises from V ₁ to V ₂ . This increase ΔV = V
_2- V ₁ corresponds to the voltage across the high resistance R _S because the potential of the sensor emitter terminal E _S of the sensor IGBT section 2 a is equal to the potential of the collector terminal C, and the sensor emitter terminal E _S is The potential at the normal time increases from 0 to ΔV. Therefore, the sensor emitter terminal E _S
When the potential of the voltage exceeds the threshold voltage of the n-channel MOSFET 3a of the detection circuit 3, this turns on, and the voltage drop of the pull-up resistor 3b causes a p-channel MOSF.
Since the ET3c is turned on, a high level logic signal is supplied to the detection terminal 1a of the gate control circuit 1, whereby the gate control signal becomes low level and the IGBT 2 is cut off. Therefore, the IGB
It is possible to prevent thermal destruction due to high power consumption of T2. In addition to the abnormality of the gate control circuit 1, when the load L is short-circuited, the potential of the sensor emitter terminal E _S rapidly rises, the detection circuit 3 operates in the same manner, and the IGBT 2 also shuts off.

[0004]

However, the above detection circuit 3 has the following problems. The detection circuit 3 and the gate control circuit 1 are also built on the chip of the IGBT 2, but the detection voltage greatly varies due to the variation in the conditions of the manufacturing process. IG with a sensor element has a chip that performs a detection operation even when the occurrence of an abnormality is slight, and a chip that does not easily operate even if the occurrence of an abnormality is severe.
In the case of BT, it was rather a cause of a decrease in the yield, as compared with the case without the sensor element. Further, since the sensor IGBT part 2a constitutes an emitter follower, a diffused resistor or a high resistance R _{S of} polysilicon is required. However, since a leak current of the sensor IGBT part 2a is unavoidably present, the high resistance R _{S is} caused. N by the voltage drop of
The channel type MOSFET 3a may be turned on even in a normal state, and the use of the high resistance R _S easily causes the malfunction of the detection circuit 3 and causes the reduction in yield in terms of reliability.

In view of the above problems, an object of the present invention is to provide a step characteristic (non-linear characteristic) at a specific voltage, which is different from that of the main element in the voltage / current characteristic of the sensor element. An object of the present invention is to provide a semiconductor device with a sensor element, which can detect an on-voltage with a large detection margin and can be surely detected, and which can improve the yield similarly to the case where no sensor element is provided.

[0006]

In general, a semiconductor device with a sensor element has a main semiconductor structure and a sensor semiconductor structure of a smaller scale than that of the main semiconductor structure independently on the same substrate. Is a basic structure including at least a bipolar transistor structure including a first conductivity type emitter semiconductor region, a second conductivity type base semiconductor region, and a first conductivity type collector semiconductor region, and a majority carrier for the base semiconductor region. Injectable MIS
And FET, respectively. In such a semiconductor device with a sensor element, the means taken by the present invention provides a high-concentration region of the first conductivity type, which partially short-circuits the base semiconductor region to the electrode which is in conductive contact with the emitter semiconductor region in the sensor semiconductor structure. It is characterized by that. This first
The formation region of the high-concentration region of conductivity type is preferably at least in a region close to the main semiconductor structure, and when the sensor semiconductor structure is a planar annular cell structure, the first conductivity type is formed. The formation region of the high-concentration region of the mold is preferably in the curved range of the annular cell structure.

When the basic structure is composed of only bipolar transistor structure, it is an IGBT. The IGBT may be a vertical IGBT, but it is preferable that the IGBT is a lateral IGBT in which the electrodes are formed on the main surface of the substrate. Further, not only the IGBT but also a thyristor structure including a reverse bipolar transistor structure sharing the base semiconductor region and the collector semiconductor region, in addition to the bipolar transistor structure.

[0008]

When the MISFETs for injecting majority carriers of the main semiconductor structure and the sensor semiconductor structure are both turned on,
The majority carriers are injected into the base semiconductor region.

As a result, the conductivity of the base semiconductor region of the main semiconductor structure is modulated, the bipolar transistor of the main semiconductor structure is turned on, and a large amount of current flows in the main semiconductor structure. Naturally, the collector
Since the collector current increases linearly when the emitter-to-emitter voltage is increased, it exhibits the linear characteristic as in the conventional case. However, even if the MISFET for injecting majority carriers in the sensor semiconductor structure is turned on, when the collector-emitter voltage is low, the bipolar transistor in the sensor semiconductor structure is not turned on and its collector current does not increase linearly. This is because in the sensor semiconductor structure, there is a high-concentration region of the first conductivity type that partially short-circuits the base semiconductor region in the electrode that is in conductive contact with the emitter semiconductor region. A short-circuit resistance is partially interposed between the sensor semiconductor structure and the base semiconductor region of the sensor semiconductor structure.
This is because even if majority carriers are injected by the ISFET, the majority carriers are extracted to the electrode. Therefore, when the collector-emitter voltage is low, the collector current of the sensor semiconductor structure stays at the value of the on-current of the MISFET. When the collector-emitter voltage is increased, the junction between the emitter and base of the bipolar transistor is forward biased due to the voltage drop of the short-circuit resistance at a certain jump voltage, and the bipolar transistor in the sensor semiconductor structure is also turned on. The current value is discrete and higher than the current value. Therefore, the collector current jumps up by a certain step width before and after this jumping voltage.

By setting this jump-up voltage as the detection voltage, since there is a step width detection margin in detecting the on-voltage, it is possible to detect the on-voltage at the time of abnormality with high accuracy and to have no sensor element. alike,
The yield can be improved. The jump-up voltage can be changed in height by changing the formation scale of the first-conductivity-type high-concentration region, so that there is a degree of freedom in setting the detection voltage.

When the formation region of the high-concentration region of the first conductivity type is in the region close to the main semiconductor structure, the bipolar transistor of the main semiconductor structure is turned on before the bipolar transistor of the sensor semiconductor structure. In order to prevent mutual interference by suppressing the bipolar transistor on the proximity region side of the sensor semiconductor structure in the high-concentration region of the first conductivity type without forming the emitter region on the proximity region side. .

Further, in the case where the sensor semiconductor structure is a planar annular cell structure, and when the formation region of the high-concentration region of the first conductivity type is within the curved range of the annular cell structure, the latch-up on the sensor semiconductor structure side occurs. Can be prevented. When the emitter region is formed in the curved range, after the bipolar transistor is turned on, the current is concentrated from the surroundings in the planar arc-shaped collector region and the voltage drop of the collector resistance is large, and the source of the MISFET is large. The parasitic bipolar transistor including the region is turned on, and latch-up is likely to occur, but the first region is included in the bending range.
Since the conductive type high concentration region is formed, latch-up can be effectively prevented.

In the case of a lateral semiconductor device such as a lateral IGBT, the high-concentration region of the first conductivity type can be formed simultaneously with the formation of the source region of the MISFET, which contributes to simplification of the manufacturing process.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an IGBT with a sensor element according to an embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a plan view showing a semiconductor structure of a lateral IGBT with a sensor element according to an embodiment of the present invention, and FIG.
3 is a cross-sectional view showing a state of being cut along the line AA ′ in FIG.
1 is a sectional view showing a state cut along the line BB 'and CC' in FIG. 1, and FIG. 4 is a sectional view showing a state cut along the line DD 'in FIG.

The lateral IGBT 100 with this sensor element
The main IGBT cell portion C _M and the sensor cell portion C _S are formed on the main surface side of the same n-type semiconductor substrate (chip) 10.

It should be noted that FIG. 1 shows only a region of the main IGBT cell portion C _M in the vicinity of the sensor cell portion C _S. The main IGBT cell section C _M and the sensor cell section C _S are separately separated as shown in FIG. 1, and have a planar annular cell structure. The cross-sectional semiconductor structure of the main IGBT cell portion C _M and the sensor cell portion C _S has an n-type semiconductor substrate (chip) 1
0 p-type base regions (transistor collector regions) 11A and 11a formed on the main surface side, and p ⁺ -type contact regions 12A formed on the main surface side in the p-type base regions 11A and 11a, 12b and the drift regions 13A, 1 which are the n-type base regions of the transistor on the outer periphery of the p-type base regions 11A, 11a on the main surface side of the n-type semiconductor substrate 10.
3a and n ⁺ -type buffer regions 14A and 14a for suppressing injection of majority carriers (electrons) surrounding the region 3a. Mainly IGBT cell unit C p ⁺ -type collector region (anode region) of the IGBT on the principal surface side in the buffer area 14A surrounding the base region 11A of _M 15A is formed. On the main surface side in the buffer region 14a surrounding the base region 11a of the sensor cell portion C _S , the p ⁺ type collector region (anode region) 15a or the n ⁺⁺ type anode of the IGBT is partially provided along the circumferential direction. The short region 30 is formed. Formation region of the anode short regions 30 are over the boundary region of the main IGBT cell portion C _M and the sensor-cell unit C _S curved range (arc range) of the annular cell structure in the (near field) side and the opposite side from that The anode short region 30 is also formed in the curved range. Therefore, the p ⁺ -type collector region 15a of the sensor cell portion C _S is formed in the remaining linear portion of the annular cell structure.

Main IGBT cell section C _M and sensor cell section C
Common collector _S (anode) electrode 16 are in ohmic contact with the collector region 15A and the anode short regions 30 of p ⁺ -type, also the main IGBT cell portion C _M of the emitter (cathode) electrode 17 and the sensor-cell unit C _S The emitter (cathode) electrode 18 of is in ohmic contact with the respective p ⁺ type contact regions 12A and 12a. In addition, the main IGBT cell portion C _M includes the p-type base region 11A.
P ⁺ -type contact region 12A partially on the main surface side of
Of the n ^{+ +} type source region 19A which is in ohmic contact with the emitter electrode 17 and the p type base region 11A sandwiched between the n ^{+ +} type source region 19A and the drift region 13A, and is formed on the main surface through the gate insulating film 20A. Silicon gate electrode 2
1A and. Similarly, the sensor cell unit C
_S also partially overlaps the p ⁺ -type contact region 12a on the main surface side of the p-type base region 11a and the emitter electrode 1
N ^{+ +} type source region 19a in ohmic contact with 8;
The gate electrode 21a made of polysilicon is formed on the main surface of the p-type base region 11a sandwiched between this and the drift region 13a via the gate insulating film 20a.

[0019] The base region 11A in the main IGBT cell unit C _M, the contact area 12A, the drift region (base region) 13A, a buffer region 14A and the collector region 15A, the equivalent circuit large scale shown in FIG. 5 p
np type bipolar transistor _Qpnp is configured,
The collector region 15A of the IGBT is the transistor Q
Corresponding to the emitter region of _pnp , the base region 1 of the IGBT
1A corresponds to the collector region of the transistor Q _pnp . Similarly, the emitter region 11a, the contact region 12a, the drift region (base region) 13a, the buffer region 14a, and the collector region 15a in the sensor cell portion C _S constitute a small-scale pnp-type bipolar transistor q _pnp , and the IGBT Collector area 1
5a corresponds to the emitter region of the transistor q _pnp , and the collector region 11a of the IGBT corresponds to the collector region of the transistor q _pnp . Like this I
Bipolar transistors Q _pnp and q _pnp , which are independently separated and have a basic structure of the same equivalent circuit, are formed in the GBT cell section C _M and the sensor cell section C _S. Then, the source region 19 in the main IGBT cell portion C _M
A, a main surface region of the base region 11A serving as a channel region, a drift region 13A serving as a drain region, and a gate insulating film 20.
As shown in FIG. 5, the A and the gate electrode 21A form an n-channel MOSFET (insulated gate field effect transistor: MISFET) F _n for injecting majority carriers (electrons) into the drift region 13A. In the sensor cell portion C _S, the source region 19a, the main surface region of the base region 11a that is the channel region, the drift region 13a that is the drain region, the gate insulating film 20a, and the gate electrode 21a are the majority carriers for the drift region 13a as shown in FIG. N-channel MOSFET for injection (f
_n ) make up.

Both the main IGBT cell section C _M and the sensor cell section C _S have the basic structure of the IGBT.
In the sensor cell portion C _S , a partial n ⁺⁺ type anode short region 30 is formed on the main surface side in the buffer region 14a. The presence of this anode short region 30 connects the drift region 13a to the collector electrode 6 via the diffusion resistance r _x of the buffer region 14a, and short-circuits the collector region (emitter of transistor) 15a partially. That is, when this part is viewed as an equivalent circuit, as shown in FIG. 5, the diffusion resistance r _x is connected between the base and the emitter of the bipolar transistor q _pnp . The value of the diffusion resistance r _x is the anode short ratio (the area of the anode short region 30 and the collector region 1).
The ratio of the area of the anode short region 30 to the sum of the area of 5a) can be adjusted.

When a high potential is applied to the gate terminal G, MO
SFET (F _n, f _n) is turned both turned on, is injected the emitter terminal E, majority carriers from E _S (electrons) pnp bipolar transistor Q _pnp, q _pnp the n-type drift region 13A, the 13a . This makes the main IGB
The conductivity of the drift region 13A in the T cell portion C _M is modulated, the pnp bipolar transistor Q _pnp is turned on, and a large current capacity current flows through the collector resistance R in the main IGBT cell portion C _M. As a matter of course, when the collector-emitter voltage is increased, the collector current increases linearly, and therefore the characteristic shown in FIG. However, M in the sensor cell section C _S
Even _{if the} OSFET f _n is turned on, if the collector-emitter voltage is low, the pnp bipolar transistor q
_pnp does not turn on and its collector current does not increase linearly. Because the diffusion resistance r _x due to the existence of the anode short region 30 is present between the base (drift region 13 a) of the _pnp bipolar transistor q _pnp and the collector electrode 16, the drift region 13
majority carriers (electrons) by a MOSFET f _{n for} a
Are injected, the majority carriers still remain in the collector electrode 16
It will be pulled out to. Therefore, the collector
When the emitter-to-emitter voltage V _CE is low, the collector current of the sensor cell portion C _S stays at the value of the on-current of the MOSFET f _n , as shown in FIG. This collector-emitter voltage V
The low voltage range of _CE is close to the characteristics of MOSFET f _n . As you increase the collector-emitter voltage V _CE, emitter and base junction of the bipolar transistor q _pnp is forward biased by the voltage drop across the diffusion resistance r _x in the voltage V _X jump, bipolar transistors q _pnp
Is turned on, and the current value I _So3 is discrete and higher than the value I _So of the collector current I _S before the jump voltage V _X. Therefore, the collector current I _S jumps by the step width ΔI _S3 before and after the jump voltage V _X. The reason why such a step width ΔI _S is exhibited is that the suppression of the IGBT operation (rate-controlling) by the anode short region 30 is broken and the jump is increased, and the collector current value in the IGBT operation at the voltage V _X is recovered and becomes actual. Because it does. here,
When the anode short-circuit rate is large (the area of the anode short-circuit region is large), the diffusion resistance r _x is small and the suppression degree of the bipolar transistor q _pnp is high, so that the jump-up increases and the voltage V _X shows a high value. When the ratio is small (the area of the anode short region is small), the diffusion resistance r _x is large and the bipolar transistor q
_Since the degree of suppression of _pnp is low, the jump is increased and the voltage V _X becomes a low value. Therefore, by adjusting the anode short-circuit rate, the jump-up can be increased and the value of the voltage V _X can be increased or decreased. The adjustment of the anode short circuit rate can be easily achieved by enlarging or reducing the scale of forming the anode short circuit region 30 as described above. Although the concentration adjustment of the anode short region 30 is also a factor for adjusting the anode short ratio, the anode short region 30 has the source region 19
It is desirable to form the source regions 19A and 19a with the same mask at the same time as the formation of the source regions 19A and 19a.
Setting a concentration different from that of a causes an additional process.

Next, the lateral IGBT 1 with the above-mentioned sensor element
The on-voltage detection operation of 00 will be described. FIG. 7 shows a circuit configuration in which the gate control circuit 1 and the detection circuit 40 are built in the substrate 10 of the lateral IGBT 100 with a sensor element. The detection circuit 40 includes the emitter electrode E _S of the sensor cell portion C _S of the IGBT 100 and the emitter electrode E of the main IGBT cell portion C _M.
A comparator having a relatively low resistance of 1000Ω or less connected to the sensor resistance r _S and a comparison voltage V _REF as an inverting input and the potential of the emitter electrode E _S of the sensor cell portion C _S as a non-inverting input ( Comparator 42).
Now, when the logic amplitude of the gate control signal from the gate control circuit 1 is normal, for example, the gate voltage V shown in FIGS.
And _G1, the collector current (energizing current) in the main IGBT cell portion C _M in the on-state when the I _C and I _1, the collector-emitter voltage V _CE of the main IGBT cell portion C _M in the ON state (ON voltage V _ON ) Is V ₁ . At this time, the sensor cell section C _S
Collector-emitter voltage V _S and its collector current I
_S is the intersection of the characteristic curve of FIG. 6 and the bias line L ₁ (V _S0,
I _S0 ). If an abnormality occurs in the gate control circuit 1 and the logic amplitude of the gate control signal is reduced to the gate voltage V _G3 shown in FIGS. 6 and 12, for example, the mutual load of the inactance load L still causes the same value. since the collector current I ₁ is going to flow to the IGBT 100, the collector-emitter voltage V of the main IGBT cell portion C _M
CE rapidly rises from V ₁ to V ₂ .

At this time, the collector-emitter voltage V _{S of the} sensor cell portion C _S and its collector current I _S are given at the intersection of the characteristic curve of FIG. 6 and the bias line L ₂ , but the intersection is in the step width. , The collector-emitter voltage V _S is V _X , and the collector current I _S is I _S3 . Roughly speaking, the jump of the sensor cell C _S rises and the voltage V _X rises.
By setting the normal state of the main IGBT cell portion C _M of the collector-emitter voltages V ₁ and abnormality of its collector-emitter voltage between V ₂ and the collector of an abnormality occurs the sensor-cell unit C _S The current I _S jumps stepwise from I _S0 to I _S3 . Sensor resistance r _s of an abnormal occurrence before
The voltage drop of R _s I _S0 is r _s I _S0 , but due to the occurrence of an abnormality, the voltage drop becomes r _s I _S3 and increases stepwise. By this step-up, the comparator 42 operates to generate a detection signal, whereby a low-level control signal is output from the gate control circuit 1 and the IGBT 100 is forcibly turned off. Here, if voltage V ₁ → V _X is set and the voltage V _X rises and is set as the detection voltage of the IGBT 100 at the time of abnormality, the IGBT 100 is automatically turned off when the detection voltage is reached. For example, when the size of the sensor cell portion C _S is 200 μm × 120 μm and the anode short circuit rate is 30%, the gate voltage V _G1 is 1
In the case of 5V, I _S0 is about 3 mA, I _S3 is about 20 mA, and the jumping up is raised and the voltage V _X is about 15 V. In order to generate the detection signal when the comparison voltage V _RE is 1V, the sensor resistance r _s may be set to 50Ω.
As described above, since the sensor cell portion C _S exhibits a stepwise current waveform when there is an abnormality such as a drop in the gate voltage or a load short circuit, the step width serves as a detection margin, and the element characteristics vary due to variations in the manufacturing process conditions. However, the detection error is absorbed in the detection margin. Therefore, highly accurate abnormality detection is realized. As a result, a yield similar to that of an IGBT without a sensor element can be obtained. Further, the sensor resistance r _s does not need to have a high resistance, and the resistance can be reduced, and the voltage drop due to the leakage current of the sensor cell unit C _S is also minute, so that the malfunction of the detection circuit can be prevented. . FIG. 8 shows the overall planar configuration of the main IGBT cell section C _M. The main IGBT cell portion C _M is formed in a peninsular structure having a long straight portion, and in this example, the size of one cell is 1100 μm × 120 μm. As shown in FIG. 9, such main IGBT cell parts C _M are arranged in an array of, for example, 10 columns per chip, and are arranged adjacent to each other.
The cell part _CM is continuous in the left part shown in FIG. The linear length of the main IGBT cell portion C _{M at} the final stage is formed to be slightly shorter than the others, and the sensor cell portion (sensor element) C _S is formed in the empty space. The size of the sensor cell portion C _S in this example is 200 μm × 120 μm. Main IGBT cell section C _M and sensor cell section C at the final stage
_Although it has a semiconductor structure independent of _S, it is necessary to shorten the wiring length of the common collector electrode 16 and the gate electrodes 21a and 21b, and in order to save space, the structure shown in FIG. As shown, the final-stage main IGBT cell portion C _M and the sensor cell portion C _S are arranged close to each other.
Here, formation region of the anode short region 30 in the sensor-cell unit C _S is over the curved extent of the annular cell structure in the boundary region (near region) of the main IGBT cell portion C _M and the sensor-cell unit C _S. Anode short region 30
Is formed on the boundary region side because the main IGBT cell portion _CM
The pnp-type bipolar transistor Q _pnp on the side is turned on before the pnp-type bipolar transistor q _pnp on the side of the sensor cell C _S , so that the anode short region 30 is formed without forming the collector region 15 a on the boundary region side. This is because the bipolar transistor q _pnp on the boundary region side is suppressed. Further, the anode short region 30 is also formed in the curved region opposite to the boundary region,
The p ⁺ -type collector region 15a of the sensor cell portion C _S is formed in the linear portion of the annular cell structure. When the collector region 15a is formed in the curved range, after the bipolar transistor _qpnp is turned on, the current concentrates from the surroundings on the planar arc-shaped emitter region 11a and the voltage drop amount of the collector resistance r is reduced. Large, source area 19
The parasitic npn-type bipolar transistor composed of a, the base region 11a, and the drift region 13a is turned on, and latch-up is likely to occur. For the purpose of preventing the latch-up of the sensor cell portion C _S due to this current concentration, the collector region 15a is not formed in the curved region, and the collector region 15 is not formed.
a is formed only in the straight line portion.

The sensor resistance r _S of the detection circuit is the substrate 1
It is made by a diffused resistance or a polysilicon resistance on 0. Thus, the emitter terminal E _S of the sensor cell unit C _S does not become external terminals, three terminals (gate terminal, a collector terminal, an emitter terminal) only located on one side of the lateral IGBT. In addition,
The formation of the partial anode short region 30 in the sensor cell portion C _S of this example is not limited to the lateral IGBT, but the vertical I
It can also be applied to GBT. However, in the lateral IGBT, the anode short region 30 is formed in the source regions 19A and 19a.
Since they can be simultaneously achieved by the formation process of (1), there is an advantage that the manufacturing is easy, and the detection circuit and the gate control circuit are easily formed.

In the above embodiment, the lateral IGBT is adopted as the semiconductor device with the sensor element, but the basic structure is p.
MCT (MOS gate control thyristor) and EST (emitter, npn type thyristor structure)
It can also be applied to switches and thyristors).

[0026]

As described above, according to the present invention, the high-concentration region of the first conductivity type that partially short-circuits the base semiconductor region is formed on the electrode which is in conductive contact with the emitter semiconductor region on the sensor semiconductor structure side. Since it is characterized by, it has the following effects.

When the collector-emitter voltage is low, the amount of voltage drop in the high-concentration region of the first conductivity type is small,
Although the bipolar transistor is in the off state, when the collector-emitter voltage is increased, the junction between the emitter and the base of the bipolar transistor is forward biased due to the voltage drop of the short-circuit resistance at a certain jump voltage, and the bipolar transistor in the sensor semiconductor structure also The current is on, and the current value is discrete and higher than the collector current before the jump voltage. By setting this jump-up voltage as the detection voltage, there is a step width detection margin for detecting the on-voltage, so the on-voltage at the time of an abnormality can be detected with high accuracy and is similar to that without a sensor element. Therefore, the yield can be improved. The jump-up voltage can be changed in height by changing the formation scale of the first-conductivity-type high-concentration region, so that there is a degree of freedom in setting the detection voltage.

When the formation region of the high-concentration region of the first conductivity type is in the region close to the main semiconductor structure,
Mutual interference between the main semiconductor structure and the sensor semiconductor structure can be prevented.

In the case where the sensor semiconductor structure is a planar annular cell structure, and when the formation region of the high-concentration region of the first conductivity type is in the curved range of the annular cell structure, the latch-up on the sensor semiconductor structure side occurs. Can be prevented.

In the case of a lateral semiconductor device such as a lateral IGBT, the high-concentration region of the first conductivity type can be formed simultaneously with the formation of the source region of the MISFET, which contributes to simplification of the manufacturing process.

[Brief description of drawings]

FIG. 1 is a lateral IG with a sensor element according to an embodiment of the present invention.
It is a top view which shows the semiconductor structure of BT.

FIG. 2 is a cross-sectional view showing a state of being cut along the line AA ′ in FIG.

FIG. 3 is a cross-sectional view showing a state of being cut along the line BB ′ and the line CC ′ of FIG.

FIG. 4 is a cross-sectional view showing a state of being cut along the line DD ′ of FIG.

FIG. 5 is a circuit diagram showing an equivalent circuit of a main IGBT cell section and a sensor cell section in the lateral IGBT with a sensor element of the same example.

FIG. 6 is a graph showing a characteristic of collector current with respect to a collector-emitter voltage of a sensor cell portion in the lateral IGBT with a sensor element according to the same example.

FIG. 7 is a circuit diagram showing a combination circuit of the lateral IGBT with a sensor element of the embodiment, a gate control circuit and a detection circuit.

FIG. 8 is a plan view showing a main IGBT cell portion in the lateral IGBT with a sensor element of the same example.

FIG. 9 is a schematic view showing a planar arrangement of a plurality of main IGBT cell parts and sensor cell parts in the lateral IGBT with a sensor element of the same example.

FIG. 10 is a circuit diagram showing a combination circuit of a conventional lateral IGBT with a sensor element, a gate control circuit, and a detection circuit.

FIG. 11 is a circuit diagram showing an equivalent circuit of a conventional lateral IGBT with a sensor element.

FIG. 12 is a graph showing characteristics of collector current with respect to collector-emitter voltage of a sensor IGBT portion of a lateral IGBT with a sensor element according to the conventional example.

[Explanation of Codes] C _M ... Main IGBT cell part C _S ... Sensor cell part 10 ... N-type semiconductor substrate 11A, 11a ... IGBT p-type base region (collector region of transistors Q _pnp, q _pnp ) 12 A, 12 a ... P ⁺ Type contact regions 13A, 13a ... Drift region (transistor Q _pnp, q
n-type base region of _pnp ) 14A, 14a ... n ⁺ type buffer region 15A, 15a ... IGBT p-type collector region (transistor Q _pnp, q _pnp emitter region) 16 ... IGBT collector (anode) electrode 17, 18 ... IGBT emitter (cathode) electrodes 19A, 19a ... n ⁺⁺ type source region 20A, 20a ... gate insulating film 21A, 21a ... gate electrode 30 ... n ⁺⁺ type anode short region r _X ... diffusion resistance R, r ... collector resistance Q _pnp, q _pnp pnp type bipolar transistor F _n , f _n n channel type MOS for majority carrier injection
FET.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location 7514-4M H01L 29/78 301 J 9055-4M 321 T

Claims (6)

[Claims] 1. A main semiconductor structure and a sensor semiconductor structure of a smaller scale than the main semiconductor structure are independently provided on the same substrate, and the main semiconductor structure and the sensor semiconductor structure have a first conductivity type emitter semiconductor region. A basic structure including at least a bipolar transistor structure including a second conductivity type base semiconductor region and a first conductivity type collector semiconductor region;
A semiconductor device with a sensor element, each of which comprises a MISFET capable of injecting majority carriers into the base semiconductor region, wherein the base semiconductor region is formed on an electrode that is in conductive contact with the emitter semiconductor region in the sensor semiconductor structure. A semiconductor device with a sensor element, comprising a high-concentration region of a first conductivity type that is partially short-circuited. 2. The semiconductor device with a sensor element according to claim 1, wherein the formation region of the high-concentration region of the first conductivity type is at least in a region close to the main semiconductor structure. Semiconductor device with sensor element. 3. The semiconductor device with a sensor element according to claim 1, wherein the sensor semiconductor structure is a planar annular cell structure,
A semiconductor device with a sensor element, wherein a formation region of a conductive type high concentration region is in a curved range of the annular cell structure. 4. A semiconductor device with a sensor element as defined in any one of claims 1 to 3, wherein the basic structure is an IGBT having only the bipolar transistor structure.
A semiconductor device with a sensor element, characterized in that 5. The semiconductor device with a sensor element according to claim 4, wherein the electrode is a lateral IGBT in which the electrode is formed on the main surface of the substrate. 6. The semiconductor device with a sensor element according to claim 1, wherein the basic structure shares the base semiconductor region and the collector semiconductor region in addition to the bipolar transistor structure. A semiconductor device with a sensor element having a thyristor structure including a reverse bipolar transistor structure.