JP3123309B2 - Semiconductor device with sensor element - 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 with a sensor element having a sensor semiconductor structure for detecting an ON voltage (operating voltage) of a main power switching element.
In particular, it relates to the improvement of the 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 for driving the power element or a load short-circuit abnormality is instantaneously detected as a change in on-voltage, and the power element is quickly shut off ( (Off state), the chip (substrate) on which the power element is built has a small scale compared to the 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 a sensor element portion (sensor semiconductor structure) having the sensor element is formed is used.
FIG. 10 shows a horizontal IGBT with a sensor element (a conductivity modulation type M).
An example of a switching circuit using an OSFET, an insulated gate bipolar transistor) is shown. In this switching circuit, the lateral IGBT 2 with the sensor element is turned on / off (open / closed) by a gate control signal from the gate control circuit 1, and, for example, an inductance load L is driven. As shown in the equivalent circuit of FIG. 11, the horizontal IGBT 2 with a sensor element is configured by connecting a main IGBT unit 2A and a sensor IGBT unit 2a in parallel. In addition,
All IGBTs are generally marked with an arrow.
Terminal is the same as a single bipolar transistor
Generally called an emitter terminal, but expressed as an equivalent circuit
Then, the emitter terminal is a bipolar transistor
Collector region is connected, and the collector terminal is bipolar.
The emitter regions of the transistors are connected.

The main IGBT section 2A has a pnp bipolar transistor Q having an emitter region connected to the collector terminal (anode terminal) C (A) of the IGBT.
_pnp , the collector region of the transistor and IGB
A collector resistance R connected between the emitter terminal (cathode terminal) E (K) of T, and an n-channel MOSFET for majority carrier injection for conducting / cutting off the emitter terminal E and the base region of the bipolar transistor Q _pnp
It is composed of a (insulated gate field effect transistor) F _n. Further, the sensor IGBT unit 2a also has its I
A pnp-type bipolar transistor q _pnp having an emitter region connected to the collector terminal (anode terminal) C (A) of the GBT, a collector region of the transistor and an IG
BT sensor emitter terminal of (sensor cathode terminal) _{E S}
A collector resistor r connected between the _{(K S),} the sensor emitter terminal _{E S} bipolar transistor _{q pnp}
And an n-channel MOSFET (f _n ) for majority carrier injection for conducting and blocking the base region. Therefore, when a high potential is applied to the gate terminal G, M
OSFET _{(F n, f} n) are both turned on,
The emitter terminal E, the majority carriers (electrons) from _{E S} p
np type bipolar transistors Q _pnp , q _pnp
Is injected into the n-type base region, and its conductivity is modulated, whereby the pnp-type bipolar transistors Q _pnp and q _pnp are turned on, and a current having a large current capacity flows through the base resistors R and r. Sensor IG
The element fabrication scale of the BT section 2a is formed much smaller than that of the main IGBT section 2A, and the sensor IGBT is formed.
The current capacity of section 2a is very small compared to that of main IGBT section 2A. The semiconductor structure of the sensor IGBT portion 2a is the same phase equal of the main IGBT portion 2A, therefore, as shown in FIG. 12, the characteristics of the collector current _{I c} for the collector-emitter voltage _{V CE} of the sensor IGBT portion 2a is also the main IGBT portion It has a similar shape to the characteristic of 2A.

[0004] has a detection circuit 3 in the switching circuit shown in FIG. 10, the sensor IGBT 2a of the collector current (substantially emitter current and the same) is the sensor emitter terminal so as to be substantially zero E _S And the main IGBT
A high-resistance sensor resistor _RS (emitter follower resistor) is connected between the emitter terminal E of the section 2A and the emitter terminal E. Therefore, the output impedance (on-resistance) of the sensor IGBT portion 2a substantially at zero, the potential of the sensor emitter terminal _{E S} of the sensor IGBT portion 2a is substantially equal to the potential of the collector terminal C. Here the gate voltage V _G1 of the during normal logic amplitude of the gate control signal shown in FIG. 12, for example from the gate control circuit 1, the collector current in the ON state (energizing current)
Is I ₁ , the collector-emitter voltage V _CE (ON voltage V _ON ) in the _{ON state} is V ₁ , but an abnormality occurs in the gate control circuit 1 and the logic amplitude of the gate control signal decreases. if, for example, becomes the gate voltage V _G3 shown in FIG. 12, the collector current I ₁ of the still same value due to mutual induction of Intakutansu load L tries to flow in the IGBT, the collector-emitter voltage of the main IGBT portion 2A V _CE rises sharply from V ₁ to V ₂ . The rise ΔV ₌ V 2 -V ₁ is the potential of the sensor emitter terminal _{E S} of the sensor IGBT portion 2a is equal to the potential of the collector terminal C, corresponds to the voltage across the high resistance _{R S,} the abnormality sensor emitter terminal E _S will rise from the potential of the normal to the [Delta] V. For this reason,
When the potential of the sensor emitter terminal _{E S} exceeds the threshold voltage of the n-channel type MOSFET3a detection circuit 3, which is turned on and the p-channel type MOSFET3c is turned on by the voltage drop across the pull-up resistor 3b, the gate A high level logic signal is supplied to the detection terminal 1a of the control circuit 1, whereby the gate control signal becomes low level and the IGBT 2 is cut off. Therefore, it is possible to prevent thermal destruction due to high power consumption of the IGBT 2 at the time of abnormality. Further, not only the abnormality of the gate control circuit 1, when the load L is short-circuited, the potential of the sensor emitter terminal E _S rises sharply, and the detection circuit 3 operates in the same manner, also IGBT2 is interrupted.

[0005]

SUMMARY OF THE INVENTION
The detection circuit 3 has the following problems. Detection times
Route 3 and gate control circuit 1 are also built on IGBT2 chip
However, due to variations in manufacturing process conditions,
Large variation in detection voltage. When the occurrence of abnormality is minor
Even if the chip that detects operation or abnormal occurrence is
Some chips do not work easily, IG with sensor element
If it is a BT, compared to a sensor without a sensor element,
This has led to a reduction in the yield. Also, the sensor
The IGBT 2a constitutes an emitter follower,
High resistance R of resistance or polysilicon_S In need of
However, the leakage current of the sensor IGBT unit 2a inevitably exists.
The high resistance R_SBy the voltage drop of
Even if the n-channel MOSFET 3a is normal, it remains on.
In some cases, the high resistance R_SUsing a detection circuit
3 is likely to cause malfunctions and low yield in terms of reliability.
I was invited below.

[0006] In view of the above problems, an object of the present invention is to provide a voltage / current characteristic of a sensor element which is different from that of a main element and which has a step characteristic (non-linear characteristic) at a specific voltage, so that an abnormal condition can be obtained. An object of the present invention is to provide a semiconductor device with a sensor element that can reliably detect an on-voltage with a large detection margin and can improve the yield as in the case of no sensor element.

[0007]

In general, a semiconductor device with a sensor element has a main semiconductor structure and a small-scale sensor semiconductor structure independently on the same substrate, and comprises a main semiconductor structure and a sensor semiconductor structure. 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. MIS that can be injected
And FETs. In such a semiconductor device with a sensor element, the means taken by the present invention is to provide a high-concentration region of the second conductivity type that partially short-circuits the base semiconductor region to the electrode that is in conductive contact with the emitter semiconductor region in the sensor semiconductor structure. It is characterized by having. This second
It is desirable that the formation region of the high-concentration region of the conductivity type be at least in a region adjacent to the main semiconductor structure. In the case where the sensor semiconductor structure has a planar annular cell structure, the second conductive region is formed. The formation region of the high-concentration region of the mold is desirably in the curved range of the annular cell structure.

[0008] When the above-mentioned basic structure consists only of a bipolar transistor structure, it is an IGBT. The IGBT may be a vertical IGBT, but is preferably a horizontal IGBT in which the electrodes are formed on the main surface of the substrate. In addition to the bipolar transistor structure, the present invention is not limited to the IGBT, and may be a thyristor structure including an inverted bipolar transistor structure sharing the base semiconductor region and the collector semiconductor region.

[0009]

When both MISFETs for majority carrier injection of the main semiconductor structure and the sensor semiconductor structure are 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, and the bipolar transistor of the main semiconductor structure is turned on, so that a current having a large current capacity flows in the main semiconductor structure. As a matter of course, when the collector-emitter voltage is increased, the collector current linearly increases. However, MISFETs for majority carrier injection in sensor semiconductor structures
When the collector-emitter voltage is low even if is turned on, the bipolar transistor of the sensor semiconductor structure does not turn on, and its collector current does not increase linearly. Because, in the sensor semiconductor structure, the second conductive type high concentration region that partially short-circuits the base semiconductor region exists in the electrode that is in conductive contact with the emitter semiconductor region.
A short-circuit resistance is partially interposed between the base and the emitter of the bipolar transistor having the sensor semiconductor structure, and the MISFET is connected to the base semiconductor region of the sensor semiconductor structure.
This is because even if majority carriers are injected, the majority carriers are extracted to the electrode. Therefore,
When the collector-emitter voltage is low, the collector current of the sensor semiconductor structure remains at the value of the ON current of the MISFET. 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 is also turned on. The current value is discrete and higher than the current. Therefore, before and after the jump voltage, the collector current jumps by a certain step width. By setting the jump voltage as the detection voltage, the ON voltage has a detection margin of the step width in the detection of the ON voltage, so that the ON voltage at the time of abnormality can be detected with high accuracy, similarly to the case where there is no sensor element. Thus, the yield can be improved. The jump voltage is
By changing the formation scale of the high-concentration region of the first conductivity type, the height can be changed, so that there is a degree of freedom in setting the detection voltage.

[0010] When the formation region of the high-concentration region of the second conductivity type is in a 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. Thus, the bipolar transistor on the proximity region side in the sensor semiconductor structure is suppressed in the high-concentration region of the second conductivity type without forming an emitter region on the proximity region side, thereby preventing mutual interference.

In the case where the sensor semiconductor structure has a planar annular cell structure, and the formation region of the second conductivity type high-concentration region is in the curved range of the annular cell structure, the latch-up on the sensor semiconductor structure side is performed. Can be prevented. When the emitter region is formed in the curved area, after the bipolar transistor is turned on, current concentrates on the planar arc-shaped collector region from around.
The voltage drop of the collector resistance is large, and the parasitic bipolar transistor including the source region of the MISFET is turned on, so that the latch-up easily occurs.
Since the high concentration region of the conductivity type 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.

[0013]

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.
FIG. 3 is a sectional view showing a state cut along the line AA ′ of FIG.
1 is a cross-sectional view showing a state cut along the line BB 'and CC' in FIG. 1, and FIG. 4 is a cross-sectional view showing a state cut along the line DD 'in FIG.

The horizontal IGBT 100 with the sensor element
A main IGBT cell portion on the principal surface side of the same n-type semiconductor substrate (chip) 10 _{C M} and the sensor-cell unit _{C S} is fabricated. Note that only the area near the sensor-cell unit C _S of the main IGBT cell portion C _M is shown in FIG. Lord I
GBT cell section C _M and the sensor cell unit C _S are separated independently as shown in FIG. 1 is a planar annular cell structure.

The cross-section a semiconductor structure of the main IGBT cell portion _{C M} and the sensor cell unit _{C S} is, n-type semiconductor substrate (chip) 1
0 p-type collector regions 11A and 11a of the bipolar transistor formed on the main surface side, and p ⁺ -type contact regions 12A formed on the main surface side in the p-type collector regions 11A and 11a. , Ba 12b and, p-type collector region 11A in the main surface side of the n-type semiconductor substrate 10, the outer periphery of the 11a
N ⁺ -type buffer regions 14A and 14 for suppressing injection of majority carriers (electrons) surrounding drift regions 13A and 13a as n-type base regions of the bipolar transistor
a. Of the bipolar transistor on the main surface side of the buffer area 14A surrounding the collector <br/> region 11A of the main IGBT cell section _{C M} ^{p +} -type emitter region 1
5A are formed. In the main surface side of the buffer region 14a surrounding the collector territory <br/> areas 11a of the sensor-cell unit C _S, partially bipolar tigers along the circumferential direction
Cathode shorting region 30 of the emitter region 15a or ^{n ++} type ^{p +} -type Njisuta is formed. Casor
Forming regions of de short region 30, the main IGBT cell portion C
Border region of the _M and the sensor cell unit C _S curvature range of cyclic cell structure in the (near field) side and over the (arc range), Cathode show <br/> preparative region 30 in bending range opposite the it Is formed. Therefore, the sensor cell section C
_{The S} p ⁺ type emitter region 15a is formed in the remaining linear portion of the annular cell structure.

[0017] A common collector main IGBT cell portion _{C M} and the sensor cell unit _{C S} (anode) electrode 16 is in ohmic contact with the emitter region 15A and the cathode short-circuit region 30 of the ^{p +} -type, also the main IGBT cell portion C
_M emitter (cathode) electrode 17 and sensor cell section C
_{The S} emitter (cathode) electrode 18 is in ohmic contact with the respective p ⁺ -type contact regions 12A and 12a. The main IGBT cell portion _{C M} is partially ^{p +} -type overlaps the emitter electrode 17 in the contact region 12A of ^{n ++} type ohmic contact source regions 19A in the main surface side of the p-type collector <br/> region 11A And a polysilicon gate electrode 21A formed on a main surface of a p-type collector region 11A interposed between the drift region 13A and the drift region 13A via a gate insulating film 20A. Similarly, the sensor-cell unit _{C S} also partially ^{p +} -type emitter electrode 18 overlaps the contact region 12a of the ^{n ++} type ohmic contact source regions 19a on the main surface side of the p-type collector region 11a, a which Gate insulating film 20 is formed on the main surface of p-type collector region 11a sandwiched between drift region 13a and drift region 13a.
a gate electrode 21a of polysilicon formed through
And

[0018] Here, in the main IGBT cell section _{C M}
Collector region 11A, the contact region 12A, the drift region (base region) 13A, a buffer area 14A and d
Emitter region 15A is the equivalent circuit constitute a large pnp-type bipolar transistor _{Q pnp} shown in FIG. 5, the emitter region 15A of the IGBT corresponds to the emitter region of the bipolar <br/> transistor _{Q pnp} , IGB
The collector region 11A of T is connected to its bipolar transistor Q
It corresponds to a _pnp collector region. Similarly, the collector region 11a of the sensor-cell unit _{C S,} the contact area 12a, the drift region (base region) 13a, a buffer area 14a and the emitter region 15a constitutes a small pnp-type bipolar transistor _{q pnp,} The emitter region 15a of the IGBT 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 . Note that IGBTs as a single unit are generally
In the symbol shown in, the terminal with an arrow
Emitter terminal and general like bipolar transistor
However, when expressed in terms of an equivalent circuit, the emitter
The collector region of the bipolar transistor is connected to the terminal
The collector terminal is a bipolar transistor emitter.
Data area is connected. Thus, the main IGBT cell section C
The _M and the sensor cell unit _{C S,} is independently separated, bipolar transistors _Q pnp forming the basic structure of the same equivalent _{circuit, q pnp} are fabricated. And
Source region 19A in the main IGBT cell unit _{C M,} the channel region serving as the base region 11A of the main surface region, the drain region serving as a drift region 13A, a gate insulating film 20A, and the gate electrode 21A, as shown in FIG. 5, the drift region 13A majority carriers (electrons) n-channel MOSFET for injection (insulated gate field effect transistor: MISFET) for constituting a _{F n.} Source region 19a of the sensor-cell unit _{C S,} the main surface region of the channel region serving as the base region 11a, the drain region serving as a drift region 13a, a gate insulating film 20a, and the gate electrode 21a
Constitutes an n-channel MOSFET (f _n ) for majority carrier injection into the drift region 13a as shown in FIG.

The main IGBT cell unit _{C M} and the sensor cell unit _{C S} of the above is both have the basic structure of IGBT, in the sensor cell unit _{C S,} the buffer area 14a
A partial n ^++- type cathode short region 30 is formed on the main surface side of the inside. This cathode short region 30
Exists between the collector electrode 16 and the buffer region 14.
Connect the drift region 13a via the diffusion resistance r _x of a, it is shorted emitter region 15a partially. That is, when this portion is viewed in terms of an equivalent circuit, as shown in FIG. 5, a diffusion resistor 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 cathode short rate (mosquitoes
The ratio can be adjusted by the ratio of the area of the cathode short region 30 to the sum of the area of the sword short region 30 and the area of the emitter region 15a.

When a high potential is applied to the gate terminal G, MO
SFET _(F n, _{f n)} is turned both turned on, the emitter terminal E, majority carriers (electrons) pn from _{E S}
The p-type bipolar transistors Q _pnp , q _pnp are injected into the n-type drift regions 13A, 13a. Thus the drift region in the main IGBT cell unit _{C M} 1
3A conductivity is modulated, pnp-type bipolar transistor _{Q pnp} current of a large current capacity in the main IGBT cell unit _{C M} flows through the collector resistor R in the ON state. Naturally, when the collector-emitter voltage is increased, the collector current linearly increases, so that the characteristic shown in FIG. However, when the ON and the collector-emitter voltage be low MOSFETf _n in the sensor cell unit _{C S} is, pnp-type bipolar transistor _{q pnp} will not turn on state, the collector current does not increase linearly. Because mosquito
Since the diffusion resistance r _x due to the presence of the sword short region 30 is interposed between the base (drift region 13 a) of the pnp type bipolar transistor q _pnp and the collector electrode 16, the MOSFE is applied to the drift region 13 a.
Even _if majority carriers (electrons) are injected by Tf _n ,
This is because the majority carriers are extracted to the collector electrode 16. Therefore, the collector-emitter voltage V
The sensor-cell unit C _S as when _CE is low 6
The collector current remains at a value of on-state current of the MOSFETf _n. Low voltage range of the collector-emitter voltage _{V CE} is similar to the characteristics of MOSFETf _n. When the collector-emitter voltage V _CE is increased, the junction between the emitter and the base of the bipolar transistor q _pnp is forward-biased by the voltage drop of the diffusion resistor r _{x at} the jump voltage V _X , and the bipolar transistor q
_pnp is turned on, as compared to the value _{I So.} the jumping voltage _{V X} before the collector current _{I S} becomes discrete high current value _{I So3.} Therefore, the jump collector current I _S is the voltage across V _X step width ΔI
_It jumps up by _S3 . Reason for showing such step size [Delta] I _S is, IGBT due to cathode shorting region 30
When the suppression (rate-limiting) of the operation is broken, its jump voltage V _X
This is because the value of the collector current in the IGBT operation in FIG. Here, when the cathode short ratio is large (the area of the cathode short region is large), the diffusion resistance r _x is small, and the bipolar transistor q _pnp
Because of the high degree of suppression, shows the voltage V _X is a high value jump, when the cathode short-circuit rate is small (small area of the cathode short regions), the diffusion resistance r _x is large, a low degree of suppression of the bipolar transistor q _pnp because, jumping voltage V _X is a low value. Therefore,
By adjusting the cathode short ratio, it is possible to increase or decrease the value of the voltage V _X jump. Cathode short region 30 as the adjustment of the cathode show <br/> DOO rate was above
This can be easily achieved by scaling the scale of formation. Mosquitoes also concentration adjustment of the cathode short-circuit region 30
Although it is an adjustment factor of the sword short ratio, the cathode short region 30 is desirably formed by the same mask at the same time as the formation of the source regions 19A and 19a. Setting different concentrations leads to additional processes.

Next, the horizontal IGBT 1 with the sensor element described above
The ON voltage detection operation of 00 will be described. FIG. 7 shows a circuit configuration in which a gate control circuit 1 and a detection circuit 40 are formed on a substrate 10 of a horizontal IGBT 100 with a sensor element. Detection circuit 40, the sensor resistance _{r S} following the relatively low resistance 1000Ω which is connected between the emitter electrode E of the emitter electrode _{E S} and the main IGBT cell portion _{C M} of the sensor-cell unit _{C S} of the IGBT 100, the comparison voltage consists a comparator 42 to the non-inverting input to the potential of emitter electrode E _S of the sensor cell unit C _S while the inverting input of V _REF.

[0022] Now, the gate voltage V _G1 of the during normal logic amplitude of the gate control signal shown in FIGS. 6 and 12, for example from the gate control circuit 1, the main IGBT cell portion C _M in the on-state collector current (energizing current ) If the _{I C} and _{I 1,} the collector of the main IGBT cell portion _{C M} in the on state,
Emitter voltage _{V CE} (ON voltage _{V ON)} is _{V 1.}
Its collector current _{I S} and the collector-emitter voltage _{V S} of the time the sensor-cell unit _{C S} is given by the intersection of the characteristic curve and the bias line _{L 1} in FIG. _{6 (V S0, I S0)} . If an abnormality occurs in the gate control circuit 1 and the logic amplitude of the gate control signal decreases to reach, for example, the gate voltage _VG3 shown in FIG. 6 and FIG.
Of the collector current I ₁ still having the same value due to mutual induction of
Since but tries to flow in the IGBT 100, the collector-emitter voltage _{V CE} of the main IGBT cell portion _{C M} is abruptly _{V 1}
It rises from up to _{V 2.} In this case the collector-emitter voltage V _S of the sensor-cell unit C _S and the collector current I
_S is given by the intersection of the characteristic curve and the bias line L ₂ in FIG. 6, at the intersection due to the step width, the collector-emitter voltage V _S is V _X, the collector current I
_S becomes _IS3 . Roughly speaking, the sensor cell section C
The main IGBT cell section C when the voltage V _X is normal when the jump of _S is normal.
By setting between the collector-emitter voltages V ₁ and the collector-emitter voltage V ₂ that of the abnormality of the _M, the collector current I _S of the abnormality occurs the sensor-cell unit C _S from the I _S0 I _S3 Bouncing step by step. Voltage drop across the sensor resistance r _s of the abnormal occurrence before r _s
Is a I _S0, the voltage drop due to the abnormal occurrence _r s I
_It becomes _S3 and rises 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.

[0023] In this case, as the voltage _{V 1} → _{V X,} if you set the voltage _{V X} as a detection voltage of IGBT100 of abnormal bounce, if the detection voltage, automatically IGBT100 is turned off. For example, the sensor-cell unit _{C S} of the size of 200 [mu] m × 120 [mu] m, a cathode sheet <br/> Yoto rate when 30%, the gate voltage _{V G1} is 15V
_{For, I S0} about _3mA, the _{I S3} is about 20 mA, jumping voltage _{V X} is about 5V. Comparison voltage V
_RE for to such detection signal when a 1V occurs, it is sufficient to set the sensor resistance r _s to 50 [Omega.

[0024] Thus, to indicate the abnormal sensor-cell unit C _S is stepped current waveform in such reduction or load short-circuit of the gate voltage, the step width is the detection margin, the device characteristics due to variations in conditions of the manufacturing process Even if there is variation, the detection error is absorbed by the detection margin.
Therefore, highly accurate abnormality detection is realized. As a result, the same yield as an IGBT without a sensor element can be obtained. Further, the sensor resistance r _s is not required a high resistance, it is possible to reduce the resistance, a voltage drop due to leakage current of the sensor cell unit C _S is also small, it is possible to prevent an erroneous operation of the detection circuit .

[0025] Figure 8 shows a plan overall configuration of the main IGBT cell portion _{C M.} The main IGBT cell portion _CM is formed in a peninsular structure having a long linear portion. In this example, the size of one cell is 1100 μm × 120 μm. Such main IGBT cell unit C _M are for example 1 chip per 10 row sequences SEQ 9, adjacent main IGB
The T cell section _CM is continuous at the left portion shown in FIG. Linear length of the main IGBT cell portion C _M of the final stage is slightly shorter form than others, the sensor-cell unit (sensor element) C _S is formed in the free space. The size of the sensor-cell unit _{C S} of the present embodiment 200 [mu] m × 120
μm. Although the main IGBT cell unit C _M and the sensor-cell unit C _S of the last stage has a mutually independent semiconductor structure,
Common collector electrode 16 and gate electrodes 21a, 21b
In order to save the wiring length and to save space, as shown in FIG.
BT cell section C _M and the sensor-cell unit C _S are arranged close.

[0026] Here, the cathode in the sensor-cell unit _{C S}
Forming regions of de short region 30, the main IGBT cell portion C
Spans curved range of cyclic cell structure in the boundary region (near region) of the _M and the sensor cell unit C _S. The reason for forming the cathode sheet <br/> Yoto region 30 in the boundary region side, the main IG
As pnp-type bipolar transistor _{Q pnp} the BT cell section _{C M} side is turned on prior to the pnp-type bipolar transistor _{q pnp} of the sensor cell unit _{C S} side, without forming an emitter region 15a in the boundary region side, Mosquito
This is because the bipolar transistor q _pnp on the boundary region side is suppressed in the sword short region 30. Also,
Also been cathode show <br/> preparative region 30 in bending range of the opposite side is formed in the boundary region, p of the sensor cell unit C _S
^{The +} type emitter region 15a is formed in a linear portion of the annular cell structure. Emitter region 15a in the bending range
Is formed, after the bipolar transistor q _pnp is turned on, the planar arc-shaped collector region 11 is formed.
With respect to a, the current concentrates from the periphery and the voltage drop amount of the collector resistance r is large, so that the source region 19a and the base region 1
1a, the parasitic npn-type bipolar transistor constituted by the drift region 13a is turned on, and latch-up is likely to occur. In order to prevent latch-up of the sensor-cell unit C _S by the current concentration, without forming the emitter region 15a in the curved extent, the emitter region 15a is formed only in a linear portion.

The sensor resistance r _S of the detection circuit is formed on the substrate 10 by using a diffusion resistance or a polysilicon resistance. 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. The formation of partial cathode <br/> short region 30 in the sensor-cell unit _{C S} of the present embodiment is not limited to the lateral IGBT, it can be applied to a vertical IGBT. However, mosquitoes in the lateral IGBT
The formation of the sword short region 30 corresponds to the source region 19A, 1
Since it can be achieved simultaneously by the formation process of 9a, there is an advantage that it is easy to manufacture, and the formation of the detection circuit and the gate control circuit is also easy.

In the above embodiment, a horizontal IGBT is used as a semiconductor device with a sensor element.
MCT (MOS gate control thyristor) having an npn-type thyristor structure and EST (emitter
Switches and thyristors).

[0029]

As described above, the present invention is characterized in that the second conductive type high-concentration region for partially short-circuiting the base semiconductor region is formed on the electrode in conductive contact with the emitter semiconductor region on the sensor semiconductor structure side. Therefore, the following effects can be obtained.

When the voltage between the collector and the emitter is low, the amount of voltage drop in the high-concentration region of the second conductivity type is small.
Although the bipolar transistor is off, when the collector-emitter voltage is increased, the junction between the emitter and the base of the bipolar transistor is forward-biased at a certain jump voltage due to the voltage drop of the short-circuit resistance. It is turned on, and has a discrete and high current value compared to the collector current before the jump voltage. By setting the jump voltage as the detection voltage, the ON voltage has a detection margin of the step width in the detection of the ON voltage, so that the ON voltage at the time of abnormality can be detected with high accuracy, as in the case where there is no sensor element. Thus, the yield can be improved. The jumping voltage can be changed in level by changing the formation scale of the high-concentration region of the second conductivity type, so that there is a degree of freedom in setting the detection voltage.

In the case where the formation region of the high-concentration region of the second 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 the formation region of the second conductivity type high-concentration region is in the curved range of the annular cell structure, the latch-up on the sensor semiconductor structure side is performed. Can be prevented.

In the case of a lateral semiconductor device such as a lateral IGBT, the high-concentration region of the second 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 the drawings]

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

FIG. 2 is a cross-sectional view showing a state cut along the line AA ′ of FIG. 1;

FIG. 3 is a cross-sectional view showing a state cut along line BB ′ and CC ′ of FIG. 1;

FIG. 4 is a cross-sectional view showing a state cut along the line DD ′ of FIG. 1;

FIG. 5 is a circuit diagram showing an equivalent circuit of a main IGBT cell portion and a sensor cell portion in the horizontal IGBT with a sensor element of the embodiment.

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

FIG. 7 is a circuit diagram showing a combination circuit of a 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 horizontal IGBT with a sensor element of the embodiment.

FIG. 9 is a schematic diagram showing a planar arrangement of a plurality of main IGBT cell portions and a sensor cell portion in the horizontal IGBT with a sensor element of the embodiment.

FIG. 10 is a circuit diagram showing a combination circuit of a conventional horizontal 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 a collector current with respect to a collector-emitter voltage of a sensor IGBT section of the lateral IGBT with a sensor element of the conventional example.

[Explanation of symbols]

C M _... main IGBT cell unit C S _... sensor-cell unit 10 ... n-type semiconductor substrate 11A, 11a ... pnp-type bipolar transistor Q
_pnp, q _pnp p-type collector regions 12A, 12a... p ⁺ -type contact regions 13A, 13a... drift regions (pn-type bipolar transistors Q _pnp, n-type base regions of q _pnp ) 14A, 14a. ⁺ Type buffer region 15A, 15a ... pnp type bipolar transistor Q
_pnp, q _pnp p-type emitter region) 16 ... IGBT collector (anode) electrode 17, 18 ... IGBT emitter (cathode) electrode 19A, 19a ... n ⁺⁺ type source region 20A, 20a ... gate insulating film 21A, 21a ... Gate electrode 30... N ⁺⁺ type cathode short region r _X ... Diffusion resistance R, r... Collector resistance Q _pnp, q _pnp .. pnp bipolar transistor F _n , f _n .
OSFET.

Claims (6)

(57) [Claims] An independent semiconductor semiconductor structure having a main semiconductor structure and a small sensor semiconductor structure in comparison with the main semiconductor structure, wherein the main semiconductor structure and the sensor semiconductor structure are a first conductivity type emitter semiconductor region, A basic structure including at least a bipolar transistor structure including a base semiconductor region of the second conductivity type and a collector semiconductor region of the first conductivity type;
A semiconductor element-equipped semiconductor device comprising a MISFET capable of injecting majority carriers into the base semiconductor region, wherein the base semiconductor region is connected to an electrode 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 the second 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 second conductivity type high-concentration region is at least 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, and
A semiconductor device with a sensor element, wherein a formation region of a conductive high-concentration region is in a curved range in the annular cell structure. 4. The semiconductor device with a sensor element according to claim 1, wherein said basic structure is formed only of said 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 horizontal IGBT formed on a 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 thyristor structure including an inverted bipolar transistor structure.