JP3254113B2 - Acceleration sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile device using a semiconductor device used at a high frequency, in particular, a Schottky barrier diode, a set of four bridge type diodes, or a semiconductor device requiring a high speed operation at a low voltage. The present invention relates to an electronic device capable of communicating with a body. An electronic device that can communicate with a moving object is, for example, a tag that includes a memory as a storage medium attached to a moving object, and information stored in the moving object by radio wave, electromagnetic induction, or optical communication when necessary. Is an electronic device that can read out any time without contact.

In particular, the present invention relates to an electronic device capable of communicating with a moving object equipped with an acceleration sensor, and an acceleration sensor having a configuration suitable for the electronic device.

[0003]

2. Description of the Related Art Conventionally, in the high-frequency band of VHF and UHF, and in the ultra-high frequency band of SHF, a Schottky barrier diode is widely used in mixers, modulators, phase detectors, and the like. A Schottky barrier diode is a type of charge for bringing the Fermi level to the same level if the difference between the vacuum level and the Fermi level (work function) differs between the metal and the semiconductor when the metal and the semiconductor come into contact. As a result of the redistribution, a space charge layer (barrier layer) is formed to have rectifying characteristics. The Schottky barrier diode utilizes this characteristic.
Since the Schottky barrier diode is superior to the PN junction diode in the response speed in the high frequency band,
It is suitable for a high-speed switching circuit and has a relatively small rising voltage as compared with a PN junction diode, so that it does not require as much input voltage as a PN junction diode.

FIG. 29 is a schematic sectional view of a conventional Schottky barrier diode. An ohmic metal 204 is formed on a low resistance, high resistance silicon substrate 201 with a Schottky metal 203 and a high impurity region 202 interposed therebetween. Usually, n-type silicon is used for the silicon substrate, and an impurity is implanted into the silicon epitaxial layer to form the high impurity region 202. Impurities are 0.8 × 10 ¹⁷ ~
Highly doped in the range of 2 × 10 ¹⁸ cm ⁻³ .

However, this type of Schottky barrier diode is difficult to use as an integrated circuit because electrodes are present on the upper and lower surfaces of the wafer. In addition, since the resistance value of the silicon substrate is high, power consumption increases. FIG. 30 is a schematic cross-sectional view of a conventional semiconductor device in which a plurality of Schottky diodes having anode and cathode electrodes on the same surface are configured. An n-type silicon epitaxial layer 206 is formed on a p-type silicon substrate 205 having a specific resistance of about 1000 Ωcm. Here, in order to electrically isolate each diode, the other portion is made porous except for the portion on the n-type silicon epitaxial layer 206 using a porosity reaction. The porous portion is converted into a porous oxide film and functions as ap ⁺ insulating film layer 207. The p ⁺ insulating separation layer 207 separates the n-type silicon epitaxial layer 206 into individual operation regions. Then, a Schottky metal 203 and an ohmic metal 204 are formed on the surface of this operation region. Also, the high impurity region 2 of the low resistance portion is connected to the ohmic metal contact portion in this operation region.
02 is formed.

FIG. 31 is a plan view of a semiconductor device in which four conventional Schottky barrier diodes are combined. Since an extra current flows between the conventional Schottky barrier diodes due to parasitic NPN,
They must be at least 200 μm apart. Assuming that the pad connected to each connection terminal is 100 μm ² , in a semiconductor device combining four Schottky barrier diodes, 1
A chip area of about 600 μm square is required.

Here, the Schottky barrier diode is set to 4
In the case where the combined semiconductor device is used as a switching device, the voltage of each Schottky barrier diode
Rise voltage in the forward direction (hereinafter referred to as V _F
Is smaller), the input voltage can be suppressed, so that power consumption can be reduced. Therefore, in the above-mentioned Schottky barrier diode, V _F
Is preferably as small as possible.

[0008] Conventional is singled out Schottky metal in order to lower the V _F of the Schottky barrier diode,
A small Schottky barrier diode of the V _F was prepared. Therefore, the conventional Schottky barrier diode is replaced by 4
Pieces combined semiconductor device selects a small Schottky metal V _F above so, the Schottky metal side anode, an ohmic metal side to form a unit of the Schottky barrier diode to the cathode, the p + isolation layer Each Schottky barrier diode is insulated, and four Schottky barrier diodes are combined in a bridge type using wire bonding or metal wiring as shown in a schematic connection diagram in FIG. 32 or FIG. It was a semiconductor device.

When connected as shown in FIGS. 32 and 33, the circuit thus constructed operates as a rectifier, and when connected as shown in FIGS. 34 and 35, it operates as a modulator. FIGS. 32 and 33 or FIGS. 34 and 35 are completely equivalent circuit diagrams. Also, as shown in FIG. 33, when the wiring of the diode bridge circuit is assembled in a cross, the wiring always crosses at one place somewhere. A three-layer structure had to be taken.

A conventional overcurrent detecting circuit, as shown in FIG. 36, has a MOS transistor 620 for detecting the voltage of a current detecting resistor 6205 connected in series to a load 6207.
3 in the control circuit 6208 in accordance with the output voltage of the switch 62.
In this circuit, the substrate of the MOS transistor 6203 is connected to the source.

As a semiconductor device suitable for low voltage and high speed operation, a MOS transistor having a sectional structure as shown in FIG. 37 is known. For example, in the case of an N-type MOS transistor, an N ⁺ -type diffusion region 7202 as a source region and an N ⁺ -type diffusion region 7203 as a drain region are provided on the surface of a P-type silicon substrate 7201. A structure in which a gate electrode 7205 is provided over a surface with a gate insulating film 7204 interposed therebetween is provided.

[0012]

[0006] However, although the conventional Schottky barrier diode mentioned above has been performed to select a Schottky metal in order to reduce the V _F, for example Ti, Cr, Au, W, etc. were unable to obtain a sufficiently low V _F is ever there is a degree of vacuum needs to be ultra vacuum such as manufacturing limitations at the time of evaporation. In the case of gallium sulfide, the surface state density is higher than that of silicon, and it is difficult to lower the forward rise voltage. Thus be sufficiently low V _F by the selection of the Schottky metal is generally could not.

In the conventional overcurrent detection circuit, when operating at a low voltage, the absolute value of the threshold voltage of the MOS transistor must be reduced. However, if the absolute value of the threshold voltage is reduced, the off-leakage of the MOS transistor is reduced. The current increases, resulting in an increase in the current consumption of the circuit. Conversely, when the absolute value of the threshold voltage is increased in order to suppress the off-leak current of the MOS transistor, there is a problem that the sensitivity of the MOS transistor decreases.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an overcurrent detection circuit which operates at a low voltage and has high sensitivity while solving the above problems. Further, in the case of a conventional MOS transistor, if the high impedance state and the low impedance state are set to, for example, 6 digits or more, the threshold voltage must be set higher than 0.5V. As a result, it has been difficult to perform high-speed operation at a power supply voltage of 1 V or less. Further, since the current path is limited to a very thin channel region on the substrate surface, the increase in current per unit area is worse than that of the bipolar transistor.

An object of the present invention is to provide a semiconductor device having a low-voltage high-speed operation and a high drive capability, which is capable of communicating with a mobile body. It is used for an electronic device, particularly for a rectifier circuit of the electronic device.

[0016]

Means for Solving the Problems In order to solve the above problems, the present invention has the following means. That is, the first
As means for (1), the semiconductor substrate is Schottky-joined via high-resistance polysilicon.

As a second means, a Schottky junction is formed on high-resistance polysilicon used as a silicon substrate.

As a third means, an extremely thin SiO ₂ layer is formed between the silicon substrate and the high-resistance polysilicon. As a fourth means, the surface of the high-resistance polysilicon is polished and smoothed to form a Schottky junction.

Further, as a fifth means, a bridge is formed by using a MOS transistor instead of a diode.

As a sixth means, a bridge is formed by using a MOS transistor having a gate and a substrate connected in place of a diode.

[0021] As a seventh means, antenna and V _F low diode or controls the power supply circuit and the memory and the reading and writing of the memory to operate at the configured rectifier circuit and a low voltage with a low V _T MOS transistor It is a data carrier composed of a control circuit.

[0022] As eighth means is composed of an acceleration sensor capable of detecting the power supply circuit and the acceleration operating in the configured rectifier circuit and a low voltage at a low MOS transistors low diode or V _T of the antenna and V _F Data carrier.

As a ninth means, an acceleration sensor is used in which the length of one side parallel to the plane from which acceleration can be detected is 1 mm or less.

[0024]

The following effects can be obtained by the above means.

[0025] According to the first to fourth means, it is possible to lower the V _F without changing the Schottky metal. Further, by the fifth means has a function of the Schottky barrier diode semiconductor device, a semiconductor device for use in high frequency and small ring mixer V _F is obtained. By the sixth means, a semiconductor device having a smaller V _F and a smaller diode bridge circuit can be obtained.

According to the seventh means, it is possible to obtain a data carrier capable of reducing the voltage loss in the rectifier circuit, reducing the load on the interrogator, and increasing the communication distance between the interrogator and the transponder.

According to the eighth means, it is possible to obtain an ever-changing environment or situation such as the acceleration of a non-contact moving object. According to the ninth means, it is possible to improve the sensitivity for detecting acceleration, force, magnitude of vibration, and the like applied to the side surface of the cylindrical object.

[0028]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention;

(First Embodiment) FIG. 1 is a schematic sectional view showing a Schottky barrier diode according to a first embodiment of the present invention. On a support substrate 1 made of quartz or silicon having an insulating film formed thereon,
As a plurality of electrically separated semiconductor substrates, a high-resistance silicon substrate, for example, an n-type silicon substrate 2 is provided, and for example, P is applied to the n-type silicon substrate 2 at 1 × 10 ¹⁴ atoms.
A high-resistance polysilicon 10 ion-implanted at a concentration of / cm ² or less is formed, and a Schottky metal 3 is formed thereon. Then, an ohmic metal 4 was formed via the Schottky metal 3 and the n ⁺ -type impurity region 5 as a high impurity region.

An n ⁺ -type impurity region 6 is formed on the surface opposite to the surface on which the Schottky junction is formed. By forming the n ⁺ type impurity region 6, the series resistance can be reduced.

FIG. 2 is a schematic cross-sectional view of a Schottky barrier diode in which an electrode that is a Schottky metal is formed via polysilicon 5501 that has not been ion-implanted into n-type silicon substrate 2. FIG. 3 shows polysilicon 5 not ion-implanted on n-type high resistance polysilicon 10.
FIG. 1 shows a schematic cross-sectional view of a Schottky barrier diode in which an electrode that is a Schottky metal is formed via 601.

(Embodiment 2) FIG. 4 is a schematic sectional view showing a Schottky barrier diode according to a second embodiment of the present invention. For example, P is 1 ×
The Schottky metal 3 was directly formed on the high-resistance polysilicon 10 ion-implanted at a concentration of 10 ¹⁴ atoms / cm ² or less, and the ohmic metal 4 was formed via the n ⁺ high impurity region 5. The effect of this is that the manufacturing cost can be reduced by using polysilicon instead of the single crystal silicon substrate. Also, in this way, V _F
Thus, a Schottky barrier diode having a small value can be obtained.

(Embodiment 3) FIG. 5 shows a third embodiment of the present invention, ie, SiO 2 of 10 ° or less.
₁ shows a schematic cross section of a diode having _two films. After forming a thermal oxide film on the n-type silicon substrate 2, for example, by performing a treatment at 80 ° C. with a mixed solution of hydrochloric acid and hydrogen peroxide solution,
An SiO ₂ layer 9 of 0 ° or less was formed, and a high-resistance polysilicon 10 and an electrode 11 were further formed thereon.

[0034] If a positive potential is applied here to the electrode 11, the storage layer due to the negative charges under the SiO ₂ film 9 is formed, the same as V _F becomes lower. When a negative potential is applied to electrode 11, and the inversion layer by the positive charge under the SiO ₂ film 9 is formed, a depletion layer is formed, in particular, the depletion layer is easy to extend at a high frequency, therefore the V _F A small diode was obtained.

Polysilicon is formed by CVD (chemical vapor deposition) under reduced pressure, and the surface thus formed has irregularities. Therefore, by polishing the surface smoothing, edge further V _F, leakage current can be reduced. Here, an n-type silicon substrate has been described as an example of the high-resistance silicon substrate, but the same effect can be obtained with a p-type silicon substrate.

Any of the diodes according to the above-described reference examples can also be used as a Schottky barrier diode semiconductor device in groups of four.

Reference Example 4 FIG. 6 shows a schematic cross-sectional view of an NMOS transistor. First, an n-type silicon substrate 2 is epitaxially grown on a support substrate 1, and a source region 12 and a drain region 13 are formed on an upper surface of the n-type silicon substrate 2 thus epitaxially grown.
Was formed. Then, a gate electrode was formed on the n-type silicon substrate 2 via an insulating film.

FIG. 7 is a schematic sectional view of an NMOS transistor having another configuration. A high-resistance polysilicon 10 was formed on the support substrate 1 to form a source region 12 and a drain region 13 respectively.

In the semiconductor device in which four NMOS transistors are combined as shown in FIG. 6 or FIG. 7, since each NMOS transistor has a plurality of semiconductor substrates electrically separated on the same support substrate, the semiconductor device is air damped. Excellent insulation separation becomes possible.

[0040] Figure 8 and the 9 or 10 11 is a schematic wiring diagram of a semiconductor device that combines four MOS transistors as described above, small V _F in this way, four sets of shots low leakage current A semiconductor device corresponding to the key barrier diode semiconductor device is obtained.

FIGS. 8 and 9 are completely equivalent circuits. With such a connection, the circuit thus assembled operates as a rectifier. FIGS. 10 and 11 are also completely equivalent circuits. With such a connection, the modulator operates as a modulator.

Reference Example 5 FIG. 12 shows a fifth reference example of a Double Balanced Mixer (Frequency Double Balanced Mixer: DB for short).
FIG. A broken line portion 1901 in FIG.
The semiconductor device of the above-described reference example is applied to the above. In the DBM, the use of diodes with irregular characteristics increases the carrier leakage and does not provide satisfactory performance. Therefore, it is important to use four diodes with uniform characteristics. As can be seen from FIG. 12, a coil is used in DBM,
As shown in FIG. 12, the connection between the input side and the output side is facilitated by using a semiconductor device in which wiring is crossed.

(Embodiment 6) FIG. 13 is a data carrier circuit diagram serving as a power supply according to a sixth embodiment. This circuit receives the transmitted signal with an antenna, and the data is temporarily stored in a capacitor.
Then, a signal is transmitted in reverse using the energy stored in the capacitor as a power supply. The semiconductor device of the reference example of the present invention is used in the rectification section of the circuit, the elements of the semiconductor device by using a small MOS transistor and the Schottky barrier diode threshold voltage V _F, fast and low-voltage A driving circuit has become possible.

Reference Example 7 FIG. 14 shows a receiving circuit according to a seventh reference example. In this circuit, the signal received by the antenna 2101 is rectified and
It is transmitted to a signal processing circuit made of MOS. The semiconductor device according to the reference example of the present invention is used for the rectifier 2102 shown by the broken line, and a high-speed and low-voltage driving circuit can be realized. The external inductor is a diode bridge semiconductor device with crossed wires as shown in FIG.
Connection becomes easy. If a micro inductor capable of operating at a high frequency is used, an inductor, a Schottky barrier diode semiconductor device, and a CMOS signal processing circuit can be integrated into one.
It can be mounted on one chip, and can be manufactured directly on an IC substrate. Similarly, in the circuits of FIG. 12 and the circuit of FIG. 13, an on-chip type circuit could be manufactured on an IC substrate by using a micro inductor for the inductor portion.

(Embodiment 8) FIG. 15 is a schematic sectional view of a semiconductor device according to an eighth embodiment in which the potentials of the gate and the substrate of a MOS transistor are wired so as to be at the same potential. Describing the structure of this semiconductor device, an n-well is formed on a p-type Si substrate 3801.
A diffusion layer or substrate 3802 was formed, and a source 3806, a drain 3807, and an n ⁺ diffusion layer 3808 were formed in the diffusion layer. An oxide film 3803 is formed on the upper surface of the p-type Si substrate
The potential of the substrate 3802 was taken by the electrode 3804 via the electrode 064, the drain 3807, and the n ⁺ diffusion layer 3808. In addition, a channel region 3809 is formed between the source 3806 and the drain 3807, and the polarity is inverted by the potential of the gate 3805 formed via the oxide film 3803 located above the channel region 3809. In the semiconductor device of this reference example, wiring is performed so that the potential of the gate 3805 and the potential of the substrate 3802 are equal.

In a normal MOS transistor, the gate 38
The potential of the gate 3805 is changed while keeping the potential of the substrate 3802 constant while keeping the potential of the substrate 3802 different from the potential of the source 3806.
The current flowing between the drains 3807 was controlled. However, the gate 3805 and the substrate 38 shown in FIG.
The source 3806 and the drain 3807 in the MOS transistor are formed by a method of wiring the potential of
The threshold voltage V _T , which is the rising voltage between the transistors, is changed to the threshold voltage V
_{With the} threshold voltage VT lower than _T , the MOS transistor is turned on, and current can flow between the source 3806 and the drain 3807. In the MOS transistor of the conventional wiring described above, the threshold voltage V _{T is obtained} by the reverse substrate effect in which the potential of the substrate 3802 is applied in a direction relatively opposite to the direction of the potential of the gate 3805.
Works in the direction of increasing. However, as shown in FIG. 15, when the gate 3805 and the substrate 3802 are wired so as to have the same potential, the gate 3805 is used.
The threshold voltage V _T of the MOS transistor acts in the direction of decreasing due to the forward substrate effect in which the potential of the substrate 3802 is applied in the same direction relatively to the direction of the potential of the MOS transistor. In other words, the gate 3805 and the substrate 382 are wired in such a manner that the potentials of the gate 3805 and the substrate 3802 are equal.
Thus, the threshold voltage V _T can be smaller than the threshold voltage according to the conventional method wired so that the potential directions of 02 are relatively different directions.

By electrically wiring the gate 3805 and the substrate 3802 so that the potentials of the gate 3805 and the substrate 3802 are equal, the threshold voltage of the MOS transistor is further reduced. In the bridge circuit, the loss voltage is reduced, and the circuit can be operated at a lower voltage.

Reference Example 9 As an example of use of a semiconductor device in which the potentials of the gate and the substrate of a MOS transistor are connected so as to have the same potential as shown in FIG. 15, overcurrent detection of a semiconductor operating at a low voltage is described. There is a circuit. FIG. 16 is a circuit diagram of an overcurrent detection circuit according to a reference example of the present invention. PMOS transistor 6
103 and the resistor 6104 are connected in series, the source of the PMOS transistor 6103 is connected to the high voltage supply terminal 6101, the source of the PMOS transistor 6103 is connected to the high voltage supply terminal 6101, and the other end of the resistor 6104 is connected to the low voltage supply terminal. 6102. A resistor 6105, a switch 6106, and a load 6107 are connected in series. The other end of the resistor 6105 is connected to a high voltage supply terminal 6101, and the other end of the load 6107 is connected to a low voltage supply terminal 6102. Connection point 61 of 6106
Reference numeral 09 is connected to the gate of the PMOS transistor and the substrate. Further, a PMOS transistor 6103 and a resistor 6
A connection point 6110 of 104 is an input of the control circuit 6108, and an output of the control circuit 6108 is an input of the switch 6106.

Next, the operation of the above configuration will be described.
The resistance of the resistor 6105 is about 50 mΩ, and a current of about 1 A normally flows through the resistor. Therefore, the voltage drop between the high voltage supply terminal 6101 and the connection point 6109 is about 0.05 V, and the connection point 6109 is a PMOS.
The gate voltage of the PMOS transistor is about 0.05 V because it is connected to the gate of the transistor. Since this is sufficiently lower than the threshold voltage normally set to about 0.2 V to 0.7 V, the PMOS transistor 6103 has a high impedance in this state, and the potential of the connection point 6110 is set to the low voltage supply terminal 6102. Is sufficiently close to this potential. From this state, the value of the current flowing through the resistor 6105 for some reason is larger than 1 A, for example, 3 A
From the high voltage supply terminal 61 at the connection point 6109
The voltage drop from the potential of 01 is about 0.15V to 0.2V
Becomes At this time, the gate voltage of the PMOS transistor approaches the threshold voltage, and the impedance of the PMOS transistor decreases. Then, the potential of the connection point 6110, which is also an input of the control circuit 6108, rises, and the control circuit 610
The output of 8 operates to turn off switch 6106, thereby preventing overcurrent from flowing.

In this operation, when the substrate of the conventional MOS transistor is connected to the source, the surface potential of the channel is between the substrate potential and the gate potential. When the board is connected,
Since the surface potential of the channel is equivalent to the gate voltage and the substrate potential, the channel can be formed efficiently. Next, the effect will be described with reference to FIG. FIG.
FIG. 7 is an operation characteristic diagram comparing the MOS transistor of the reference example with a conventional MOS transistor. Comparing the operating characteristic 6001 according to the present invention with the conventional operating characteristic 6002, there is not much difference when the gate voltage is 30 mV or less (off-leakage range).
At 0.25 V, the drain current value is improved by about one digit. With this improvement, in the overcurrent detection circuit of the present invention, it becomes possible to start the operation of the control circuit 6108 when the voltage drop at the connection point 6109 is small, so that a low voltage operation and high sensitivity can be achieved.

First, the data carrier will be described.
This data carrier technology is a technology in which a card or tag storing information is attached to a moving object, and the information is read out by radio wave, electromagnetic coupling, or optical communication in a non-contact manner. For this purpose, there are an interrogator for issuing an instruction, and a transponder for receiving an instruction integrated with an object and transmitting information. The interrogator and the transponder are located at spatially separated places, and the transmission means between them uses mainly radio waves. Thus, such an information medium that can be carried and read and written without contact using radio waves or light as a transmission means is called a data carrier. For this reason, the data carrier is capable of individually recognizing people and objects and reading and writing attribute information from a remote place, and thus has an enormous merit of being able to identify moving individuals of people and objects. Transmission media between the interrogator and the transponder are generally divided into three types: an electromagnetic induction type, an optical type, and a microwave type.

In the case of the electromagnetic induction system, a coil is used in the transmission / reception circuit, and when the magnetic flux crossing the current path changes, the electromotive force is induced. Can be induced in response to the changed current and at the same time draw electricity. Power is supplied and data is transmitted and received using this electromagnetic induction. In this system, communication is performed at a distance of several millimeters to several tens of millimeters by coils that are close to each other, but the frequency is
From 00 kHz to several MHz.

A data signal transmission system using the electromagnetic induction system will be described. For transmission and reception of information, a serial transmission signal from an interrogator is modulated to a predetermined frequency by a transmission circuit and sent to a transmission coil. The modulation method is the ASK method of turning on / off the signal of the frequency transmitter in accordance with the information, or the information of two different frequency signals is given to one frequency of logic 0 and the frequency of logic 1 is given different frequencies and switched. There is an FSK method. The information of the interrogator is modulated and sent out from the transmitting coil, and the induction signal received by the receiving coil is demodulated to the original digital signal by the demodulator of the receiving circuit. The demodulated serial signal is converted to a parallel signal by a serial / parallel converter, and a memory controller controls writing and reading in the memory and stores information in the memory at the same time.

In the optical system, both the interrogator and the transponder are provided with a light-emitting element and a light-receiving element.
Since a photodiode is used for the ED and light receiving element,
The light becomes near infrared. On the interrogator side, the driving circuit drives the light emitting element with respect to the input pulse waveform to emit light. The emitted light is detected by the light receiving element on the transponder side, becomes a large signal by the amplifier, and the original waveform is restored through a detection circuit, a waveform shaping circuit, and the like. Similarly, when a signal is returned from the transponder side, the light emitted from the light emitting element on the transponder side is received by the light receiving element on the interrogator side, and the signal is restored using an amplifier. Although the optical system is strong against electromagnetic noise, it is susceptible to dirt such as water or oil or disturbance light, and communication is not possible if light is blocked, and it is almost impossible to eliminate batteries.

The microwave system uses a radiated electromagnetic field (so-called radio wave) of a quasi-microwave of 2.45 GHz allocated for identification of a mobile body in the private radio equipment as an information transmission medium. In this method, the communication distance between the antenna on the interrogator side and the antenna on the responder side is 2 to 3 m, and sharp directivity is obtained. Are suitable. The interrogator and the transponder are used by changing the plane of polarization for transmission and reception with one attached antenna. The frequency in the 2.45 GHz band is a communication band particularly set for identifying a moving object, and is legally protected, so that stable communication can be expected. However, there is a disadvantage in that the conductor is easily reflected by the conductor and cut off by the human body.

(Tenth Embodiment) FIG. 18 is a block diagram of a data carrier according to a tenth embodiment of the present invention. This system is composed of an interrogator that issues a command signal in a system called a data carrier or RF-ID, and a transponder that sends back data in response to the received command signal. The above semiconductor device is used in the rectification section of the circuit, it allows fast and low-voltage drive circuit of each element of the semiconductor device by using the small MOS transistors and Schottky barrier diode threshold voltage V _T Thus, the loss of current in the rectifier circuit is reduced. Further, when the power supply circuit used for this data carrier can operate at a low voltage, the data carrier itself can operate at a low voltage together with a rectifier circuit capable of driving at a low voltage. As a result, communication over a longer distance than the previous data carrier becomes possible, and power consumption in the interrogator can be suppressed, thereby improving power transmission efficiency.

FIG. 18 shows a part A of the semiconductor device integrated into one chip. By forming a rectifier circuit or a modulator operating at a low voltage like the part A, a power supply circuit operating at a low voltage, and a control circuit for controlling a signal output to a memory on one chip, the cost is reduced and the chip area is reduced. It is applied to places such as mobile devices or data carrier tags, because it is much smaller.

FIG. 19 is a block diagram showing the system configuration of the tag section of the data carrier. The rectifier circuit, control circuit, and power supply circuit shown in part A of FIG. 18 correspond to part A shown by a broken line in FIG. The data carrier tag shown in FIG.
Built-in EPROM. Coil L as antenna part
Is used, and communication is possible without a battery by an electromagnetic induction method. The internal circuit configuration is a full-wave rectifier circuit, constant voltage circuit, ASK data demodulation circuit, carrier pulse extraction circuit,
Communication logic, memory blocks including EEPROM,
It incorporates a minimum operating voltage detection circuit and a residual vibration absorption circuit that is a data transmission function.

[0059] In the full-wave rectifier circuit 6301 in FIG. 19, and a small Schottky barrier diode having V _F,
By using the semiconductor device having a low rectifying characteristics rising voltage represented by a small MOS transistors V _T such connects the gate and the substrate, the current consumption in the full-wave rectifier circuit 6301 than the conventional Since it is possible to reduce the power consumption of the data carrier tag itself, it is possible to reduce the power consumption of the data carrier tag itself.As a result, if the communication distance is the same, the power consumption of the interrogator including the controller unit is reduced. It is possible to do.

(Eleventh Embodiment) FIG. 20 is an image diagram of a very small data carrier according to an eleventh embodiment of the present invention. Capsule 4001 in FIG.
The memory 400 such as the antenna 4002, the power supply circuit 4003, and the EEPROM shown in the block diagram of FIG.
4 and a rectifier circuit and a control circuit. The radius of the cylinder of this elongated chip is about 0.5 mm, and the antenna 4
If an ultra-small winding bar antenna is used for 001, it can be mounted in an elongated chip with a cylindrical radius of 0.5 mm or less.

The ultra-compact, battery-less data carrier thus produced may be used not only for animal breeding management but also as a human embedded ID.
In other words, data such as passports, driver's licenses, and qualifications or careers possessed by a person as the ID of a person are incorporated into this ultra-compact data carrier, and the data carrier is embedded and used in the human body. It becomes possible.

The ultra-small data carrier may be used as a power source of a micromachine expected to be used in the field of medical equipment such as operating in a human body or a blood vessel. By embedding a carrier in the body of a competing human, more accurate measurement and timing in the competition can be achieved.

In the data carrier as described above, it was possible to read and write information in the memory attached to the moving object, but the environment around the transponder where the ever-changing moving object is placed or I couldn't draw on the situation. Therefore, an information transmission system for reading out real-time data such as sensors and indicators in a non-contact manner will be described below.

[0064] (Embodiment 1) FIG. 21 is a block diagram of a data carrier equipped with an acceleration sensor according to the present invention. Controller and antenna marked on the left side is the interrogator issues a command signal. The interrogator receives a command through a higher-level interface, and issues the command signal from the antenna to the transponder. This is a transponder in which the antenna, the rectifier circuit, the power supply circuit, and the acceleration sensor written on the right side are attached to the moving body. The semiconductor device of the above-described reference example is applied to the rectifier circuit drawn in the transponder. Each element of the semiconductor device, by using a small MOS transistor and the Schottky barrier diode threshold voltage V _T, enables high-speed and low-voltage driving circuit, the threshold voltage V _T min in the rectifier circuit Power loss is reduced. The transponder receives the command signal emitted from the interrogator by an antenna, is rectified by a rectifier circuit using the semiconductor device of the present invention, enters a power supply circuit, and generates a reference voltage Vcc. The reference voltage Vcc generated by the power supply circuit becomes the input voltage of the acceleration sensor. When the output of the acceleration sensor becomes an analog signal as shown in FIG. 26, it is A / D converted and converted into a digital signal output. When a comparator is included in the output circuit of the sensor, the output becomes a digital signal as it is. The signal received by the antenna is temporarily stored in a capacitor. When the signal has been completely transmitted from the interrogator, the response signal is returned from the transponder to the interrogator using the energy stored in the capacitor as a power source. Then, the interrogator receiving the signal transmits the data to the upper interface. With such a configuration, it is possible to detect the magnitude of the acceleration or force applied to the moving body in a non-contact manner without mounting a battery on the transponder.

FIG. 22 is a perspective view of an acceleration sensor section of a data carrier having an acceleration sensor according to a reference example of the present invention. This acceleration sensor includes a Si substrate 2806 on which a diffusion resistor 2802 is formed, a weight 2801 serving as a weight of a cantilever, and a support substrate 2805. The Si substrate 2806 receives the acceleration 280
Since 1 has a cantilever shape, the direction becomes the direction in which the acceleration is received. Therefore, the diffusion resistance 2802 embedded in the beam portion of the cantilever receives a stress proportional to the acceleration, and changes with respect to the stress applied with the resistance value of the diffusion resistance 2802. This electrical change is transmitted to the support substrate 2805 through the pad 2803 and the wire bonding 2804. The Si substrate 2806 is divided into a sensor portion and a support portion with the beam portion upside down. The support portion of the acceleration sensor is attached to the support substrate 2805 and is completely fixed.

FIG. 23 is a perspective view of an acceleration sensor section of a data carrier having an acceleration sensor according to an embodiment of the present invention. The acceleration sensor shown in FIG. 23 includes a Si substrate 3401 on which a diffusion resistor 3404 is formed, an upper support substrate 3402, and a lower support substrate 3403. In this acceleration sensor, the Si substrate 3401 has a diffusion resistance 3404
The patterning surface on which is formed is placed sideways, and the laterally oriented Si substrate 3401 is fixed by sandwiching a support substrate upper portion 3402 and a support substrate lower portion 3403. For that purpose, the upper support substrate 3402 or the lower support substrate 3403
When an acceleration in the vertical direction is applied to the bonding surface between the Si substrate 3401 and the Si substrate 3401, the Si substrate 3401 is distorted in the direction in which the acceleration is applied, and a stress proportional to the acceleration is applied to the diffusion resistor 3404. As a result, the resistance value of the diffusion resistor 3404 changes with respect to the applied stress, and the output voltage changes in proportion to the acceleration. Since the Si substrate 3401 is obtained by laying chips obtained by cutting a Si wafer into a length L and a width W sideways, t in the figure is the thickness of the Si wafer itself. It is also possible to make the thickness smaller than the thickness of the Si wafer. If W is reduced, the sensitivity of the sensor can be improved. However, since there is a limit in dicing processing accuracy, W is limited to about 100 μm.

FIG. 24 is a circuit diagram of an acceleration sensor section of a data carrier on which the acceleration sensor of the present invention is mounted. FIG.
The diffusion resistance 2802 drawn on the acceleration sensor of FIG.
Is a variable resistor of the bridge circuit 2901 depicted in FIG. When acceleration is applied to the acceleration sensor, the resistance value of the variable resistor of the bridge circuit 2901 changes.
Also changes in proportion to the magnitude of the acceleration applied to the acceleration sensor. The output voltage of bridge circuit 2901 is amplified to some extent by preamplifier 2902. The amplified signal passes through a temperature compensation circuit 2903 and is amplified by a final amplifier 2904 to a desired sensitivity.

FIG. 25 is a circuit diagram of an acceleration sensor section of a data carrier equipped with the acceleration sensor of the present invention. This circuit diagram is a circuit assembled for an acceleration sensor having a diffusion resistance that receives a tensile stress and a compressive stress when an acceleration is applied in a certain direction, such as the acceleration sensor depicted in FIG. is there. Diffusion resistance, which increases in resistance under tensile stress, decreases in resistance under compressive stress, and diffusion resistance, which increases in resistance under compressive stress, decreases in resistance under tensile stress. In the Si sensor 3401 of the acceleration sensor depicted in FIG. 23, when acceleration is applied from above the paper surface to below the paper surface, the diffusion resistance 3404 provided on the upper side of the Si substrate 3401 receives a tensile stress and is attached below the Si substrate 3401. The diffusion resistor 3404 receives a compressive stress. When an acceleration is applied from below the paper surface to the paper surface, opposite stresses are applied to each. In this way, the bridge circuit 35 is combined with the diffusion resistor having the resistance value change in the opposite direction as shown in FIG.
01 is assembled. Thus, when acceleration is applied to the acceleration sensor, the resistance value of the variable resistor of the bridge circuit 3501 changes, and the output voltage of the bridge circuit 3501 also changes in proportion to the magnitude of the acceleration applied to the acceleration sensor. The output voltage of bridge circuit 3501 is amplified to some extent by preamplifier 3502. The amplified signal is output to the temperature compensation circuit 3
Through 503, the signal is amplified by the final amplifier 3504 to a desired level of sensitivity.

FIG. 26 is an output characteristic diagram of the acceleration sensor section of the data carrier on which the acceleration sensor of the present invention is mounted.
This output voltage is an output voltage passed through the circuit shown in FIG. The output voltage when no acceleration is applied is set to 0V, and the output voltage when + 1G is applied is 2V.
The output voltage when V and -1G are applied is set to a sensitivity of -2V. Thus, in the ideal characteristic diagram, an output voltage proportional to the acceleration applied to the acceleration sensor can be obtained.

In the above, the mounting of a sensor device such as an acceleration sensor has been described in place of the memory and the control circuit for controlling the memory. However, when an indicator such as a buzzer or an LED is mounted and a signal is received, a sound is generated. It is also possible to add a function of emitting light or emitting light.

FIG. 27 is a cross-sectional view of a reference example of the present invention when measuring vibration of a cylindrical system. As shown in FIG. 27, when an acceleration sensor is attached to the side surface of a cylindrical object toward the axis of the cylindrical system so that acceleration can be detected, vibration in the side direction from the axis of the cylinder can be detected. The magnitude of the vibration in the direction can be detected in real time. Here, if the width of the acceleration sensor is wide, the detection range of the vibration becomes the size of the range of the angle β shown in FIG. If the detection range is large, the magnitude of the vibration in the other direction in addition to the magnitude of the vibration in the target direction is also widened, so that the sensitivity of the magnitude of the vibration in the target direction is reduced and the error increases. In the measurement of vibration of a cylindrical system using a conventional acceleration sensor, the width of the acceleration sensor required a width of 1 mm or more, so that vibration in the range of the angle β corresponding to the width was detected. .

FIG. 28 is a sectional view when measuring the vibration in the side direction of the cylindrical system using the acceleration sensor of the reference example shown in FIG. As shown in FIG. 28, when measuring the vibration in the side direction of the cylindrical system, when an acceleration sensor is attached to the side of the cylindrical object with the surface capable of detecting acceleration facing the axis of the cylindrical system, the measurement range is as follows. The magnitude of vibration in a range corresponding to the magnitude of the angle α corresponding to the width of the acceleration sensor is detected. Therefore, when the width of the acceleration sensor that determines the range of the vibration measurement is reduced, the vibration measurement range angle α is also reduced, and the sensitivity of the magnitude of the vibration in the target direction can be improved, and the error can be reduced. Since the width of the acceleration sensor used in the present invention is formed by a chip having a width of 1 mm or less, the measurement range is narrower and narrower than when a vibration system is measured using an acceleration sensor having a large width as in the related art. Therefore, it is possible to improve the sensitivity of vibration in a target direction.

In addition, by mounting the acceleration sensor having such a narrow measurement range on the acceleration sensor of the system as shown in FIG. 21 when measuring the vibration system in this way, the target direction of the vibration system can be measured. It is possible to read the force, acceleration or vibration with high sensitivity and without contact at any time.

A system for measuring a vibration system in a non-contact manner using such an acceleration sensor is applied in various fields. For example, daily goods are used to control the vibration of a washing machine, and ABS control and motor or engine control can be performed as a part of a car in a non-contact manner.
Control becomes possible. Also, the use of a pressure sensor makes it possible to measure the tire pressure of a car in a non-contact manner.

[0075]

As described above, a Schottky barrier diode having a small threshold voltage and an excellent isolation can be obtained, thereby obtaining a Schottky barrier diode semiconductor device having a low voltage, low power consumption and low cost.

Further, it is possible to read out a constantly changing situation such as the acceleration applied to the moving body or the temperature around the non-contacting body without contact. Further, since the surface potential of the channel formation region of the MOS transistor is controlled by both the gate voltage and the voltage applied to the substrate, an overcurrent detection circuit that can operate with high sensitivity and low voltage can be obtained.

Further, by synchronously applying a voltage having the same characteristic as the gate voltage to the channel formation region, a semiconductor device which operates at high speed and at low voltage can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a Schottky barrier diode of a first reference example.

FIG. 2 is a schematic cross-sectional view showing a Schottky barrier diode having another configuration according to the first reference example.

FIG. 3 is a schematic cross-sectional view showing a Schottky barrier diode having another configuration according to the first reference example.

FIG. 4 is a schematic sectional view showing a Schottky barrier diode of a second reference example.

FIG. 5 is a schematic sectional view showing a diode of a third reference example.

FIG. 6 is a schematic sectional view showing an NMOS transistor of a fourth reference example.

FIG. 7 is a schematic sectional view showing an NMOS transistor having another configuration according to the fourth reference example.

FIG. 8 is a schematic connection diagram showing a semiconductor device in which four MOS transistors are combined.

FIG. 9 is a schematic connection diagram showing a semiconductor device in which four MOS transistors are combined.

FIG. 10 is a schematic connection diagram showing a semiconductor device in which four MOS transistors are combined.

FIG. 11 is a schematic connection diagram showing a semiconductor device in which four MOS transistors are combined.

FIG. 12 is a circuit diagram illustrating a double balanced frequency mixing modulator according to a fifth reference example.

FIG. 13 is a circuit diagram illustrating a data carrier serving as a power supply according to a sixth reference example.

FIG. 14 shows a receiving circuit including a signal processing circuit according to a seventh reference example.

FIG. 15 is a schematic sectional view showing a schematic structure of a semiconductor device according to an eighth reference example.

FIG. 16 is a circuit diagram of an overcurrent detection circuit according to a ninth reference example.

FIG. 17 shows a MOS transistor according to a reference example and a conventional M transistor.
FIG. 9 is an operation characteristic diagram comparing OS transistors.

FIG. 18 is a block diagram of a data carrier according to a tenth reference example.

FIG. 19 is a block diagram illustrating a system configuration of a tag unit of the data carrier.

FIG. 20 is an image diagram of an ultra-compact data carrier as an eleventh reference example.

FIG. 21 is a block diagram of a data carrier equipped with an acceleration sensor according to the present invention.

FIG. 22 is a perspective view of an acceleration sensor unit of a reference example .

FIG. 23 is a perspective view of an acceleration sensor unit according to an embodiment of the present invention.

FIG. 24 is a circuit diagram of an acceleration sensor section of a data carrier equipped with the acceleration sensor of the present invention.

FIG. 25 is a circuit diagram of the acceleration sensor unit equipped with data carriers acceleration sensor of the present invention.

FIG. 26 is an output characteristic diagram of a data carrier acceleration sensor equipped with the acceleration sensor of the present invention.

FIG. 27 shows a cylindrical acceleration sensor as a reference example of the present invention.
It is sectional drawing at the time of carrying out a vibration measurement mounted in a system .

FIG. 28 is a cross-sectional view when measuring the vibration in the lateral direction of the cylindrical system using the acceleration sensor of the reference example of the present invention.

FIG. 29 is a schematic sectional view showing a conventional Schottky barrier diode.

FIG. 30 is a schematic cross-sectional view of a conventional semiconductor device in which a plurality of Schottky diodes having anode and cathode electrodes on the same surface are configured.

FIG. 31 is a plan view showing a semiconductor device in which four conventional Schottky barrier diodes are combined.

FIG. 32 is a schematic wiring diagram showing a semiconductor device in which four conventional Schottky barrier diodes are combined.

FIG. 33 is a schematic wiring diagram showing a semiconductor device in which four conventional Schottky barrier diodes are combined.

FIG. 34 is a schematic wiring diagram showing a semiconductor device in which four conventional Schottky barrier diodes are combined.

FIG. 35 is a schematic connection diagram showing a semiconductor device in which four conventional Schottky barrier diodes are combined.

FIG. 36 is a circuit diagram of a conventional overcurrent detection circuit.

FIG. 37 is a sectional view of a conventional semiconductor device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 support substrate 2 n-type silicon substrate 3 Schottky metal 4 ohmic metal 5 n + type high impurity region 6 n + type impurity region 7 insulating film 8 SOI substrate 9 SiO2 film 10 high resistance polysilicon 11 electrode 12 source region 13 drain region 14 gate electrode 15 p-type well 2801 weight 2802 diffusion resistor 2803 pad 2804 wire bonding 2805 support substrate 2806 Si substrate 2901 bridge circuit 2902 preamplifier 2903 temperature compensation circuit 2904 final amplifier 3401 Si substrate 3402 upper support substrate 3403 lower support substrate 3404 Diffusion resistor 3501 Bridge circuit 3502 Preamplifier 3503 Temperature compensation circuit 3504 Final amplifier 5501 Non-doped polySi 5601 Non-doped polySi 6101 High voltage Feeding terminal 6102 low voltage supply terminal 6103 PMOS transistor 6104 resistors 6105 resistors 6106 switch 6107 load 6108 control circuit 6109 connection point 6110 connection point 6203 MOS transistor 6204 resistors 6205 resistors 6206 switch 6207 load 6208 control circuit 6301 full-wave rectifier circuit

──────────────────────────────────────────────────の Continued on the front page (31) Priority claim number Japanese Patent Application No. Hei 7-14738 (32) Priority date January 31, 1995 (Jan. 31, 1995) (33) Priority claim country Japan (JP) (31) Priority claim number Japanese Patent Application No. 7-79176 (32) Priority date April 4, 1995 (1995.4.4) (33) Priority claim country Japan (JP) (72) Inventor Keiji Sato 1-8-8 Nakase, Mihama-ku, Chiba-shi, Chiba Seiko Electronic Industries Co., Ltd. (72) Inventor Yoshikazu Kojima 1-8-1, Nakase, Mihama-ku, Chiba-shi, Chiba Seiko Electronic Industries Co., Ltd. 1-8-8 Nakase, Mihama-ku, Chiba Seiko Electronic Industries Co., Ltd. (56) References JP-A-59-158566 (JP, A) JP-A-2-95266 (JP, A) JP-A-3-51733 (JP) , a) (58) investigated the field (Int.Cl. ^7, B name) H01L 29/84 G01L 7/00 - 23/32 G01L 27/00 - 27/02

Claims (2)

(57) [Claims] A silicon substrate fixedly sandwiched between an upper support substrate and a lower support substrate; a diffusion resistor provided on a side surface of the silicon substrate sandwiched between the upper support substrate and the lower support substrate; wherein the upper support said acceleration constituting the silicon substrate
The direction perpendicular to the surface between the substrate and the lower support substrate
The acceleration is characterized in that the diffusion resistance has a first diffusion resistance disposed above the side surface and a second diffusion resistance disposed below the side surface. Sensors. 2. A silicon substrate fixedly sandwiched between an upper support substrate and a lower support substrate, a diffusion resistor formed on a side surface of a surface of the silicon substrate sandwiched between the upper support substrate and the lower support substrate, Wherein the acceleration detects an acceleration in a direction perpendicular to a surface interposed between the upper support substrate and the lower support substrate constituting the silicon substrate, and the diffusion resistance is a first diffusion resistance and An acceleration sensor having a second diffusion resistance which receives a stress opposite to the first diffusion resistance.