JPS5872059A - Semiconductor device and its manufacture - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to integrated semiconductor devices in the field of sensors and sources of radiation of electromagnetic energy, and in particular to new microscopic spaces (MICRs) in applications involving sensing.

The present invention relates to an integrated semiconductor device that can also integrate a signal processing circuit that provides f and a method for manufacturing the same. The semiconductor device of the present invention, which may also be manufactured by a patch process, has a much larger thermal and Physical insulation is provided, and a thermal-to-thermal transformer is attached to the semiconductor circuit chip.
-electric transducer) or static electric element (5tatic electric ele)
A space where environmental products can be accumulated (environment)
). The invention has application in the technical fields of flow detection, combustible gas detection, humidity detection and pressure detection. However, the invention is not limited to these fields.

The present invention relates to a semiconductor device and a method for manufacturing the device.

A semiconductor device of the present invention has a semiconductor substrate with a recess formed in a first surface. Further, the semiconductor device has a member constituting a thermoelectric transformer saucer or an electrostatic element, and the member has a PJ [a predetermined configuration provided at a certain distance] above the recess. There is. The member is connected to the first surface in at least one location, and the recess has an opening around at least a portion of the predetermined configuration, the recess being operatively connected to the member and the semiconductor body. It provides physical and thermal insulation between the

In this manner, the integrated semiconductor device provides a substantial physically and thermally isolated space between the transducer or component and the semiconductor body.

A method of manufacturing such a device includes the steps of providing a semiconductor device having a first surface having a predetermined orientation with respect to the crystal structure of the semiconductor body. The method further includes the step of providing a layer of material forming the member on the first surface (21). The method also includes at least one portion of the first surface.
The exposed surface area d1 is partially defined by predetermined features to be provided at a distance PJr. The predetermined configuration is oriented such that undercutting by anisotropic etching occurs in a substantially minimal amount of time. Finally, the method undercuts the component by anisotropically etching the exposed surfaces to create a gap.

This application describes various embodiments of the invention, and as mentioned above, the invention can be applied in technical fields such as flow sensing, combustible gas sensing, humidity sensing and pressure sensing. The applications of these patents are discussed in detail below, and the general device of the present invention and methods of manufacturing the device are described.

First, an example applied to a flow sensor will be described.

For many years, thermal anemometry has been an effective means of measuring fluid flow. By definition, a thermal anemometer relies on its heat conduction in operation. Typically, a resistance element with a temperature sensitive resistance is placed in the fluid flow. The current flowing through the resistive element causes power dissipation (electric
(al power dissipation), the temperature of the resistance element increases. The fluid to be monitored is thermally swept away from the resistive element by its flow. The final temperature of the resistive element, indicated by measuring the resistance value, is a function of fluid velocity and thermal conductivity.

Conventional resistance value change elements are usually heat wires or heat films.

It is a thermistor type. Ideally, a thermal anemometer would be a resistance transducer that is not resistant, but has a very fast response, is accurate, and is robust.

These demands are often in conflict with each other, as demonstrated by the conventional thermal wind speed η1''.Cheap anemometers are usually bulk type detectors and have poor response time characteristics. Most anemometers are expensive and carry fragile sensing elements. Accurate anemometers typically require complicated and expensive assembly of the sensing element and support structure. The meter must be fully inserted into the area where the fluid is flowing to prevent it from coming off, and therefore debris.

Susceptible to destruction or deterioration by impact from lint or other debris.

The thermal wind needle or flow transducer of the present invention comprises:
It satisfies all the characteristics required of an ideal converter in a form close to ideal. According to the invention, the wind speed needle is manufactured using a silicone-commissible process (5ilicon).
They are inexpensive, can be manufactured by low-cost patch processes such as Improved sensitivity to large changes in value and improved signal to noise ratio
ratio), it outperforms conventional solid-state thermal anemometers. Therefore, the structure is such that it has to penetrate completely into the fluid flow, so that dirt, lint, and other debris are not likely to collide. It will flow near the detection element. The anemometer of the present invention is less susceptible to performance degradation than conventional thermal anemometers.

Hereinafter, practical examples of the anemometer of the present invention will be explained in detail with reference to the drawings.

1 and 2 are side cross-sectional views of a preferred embodiment of a 70-sensor according to the present invention. Single crystal (mono
-crystalline) semiconductor 10 has a first surface 14 covered with a dielectric layer 12, such as silicon nitride. In an exemplary embodiment, element 22 of FIG.
2 is covered with a dielectric layer 18 of silicon nitride.

Dielectric layer 12 provides 11 isolation between element 22 and semiconductor 10, and 6% body layers 12 and 18 provide paslvation to element 22. By forming the depression 20 under the grid 16, sufficient thermal and physical insulation is provided between the grid 16 of the resistive (25) element and the semiconductor 10. Recess 20 is typically formed using a custom etching technique as described below. Without this depression 20, it is difficult to obtain sufficient thermal and physical insulation between the grid 16 of the sensing element and the semiconductor 10. For example, if the grid 16 of the resistive element is connected to the semiconductor 1 by only a solid dielectric layer,
Since the thermal conductivity of a solid dielectric is usually much greater than that of air, the grid 16 of resistive elements substantially conducts heat to the semiconductor 10. It turns out.

Sufficient thermal and physical isolation between the detection confectionery grid 16 and the semiconductor 10 has many advantages, making it adaptable to a wide variety of devices such as sensors. For example, in the case of the semiconductor-based flow sensor of the present invention, by constructing a very thin sensing element that is sufficiently thermally insulated from the semiconductor substrate, the sensing element can be made to withstand the flow of air raids. It has been adapted (26) to allow very sensitive measurements. This is because the temperature of thinly formed parts is easily influenced by air flow.

This is in contrast to solid state thermal anemometers which have sensing elements that allow substantial heat to escape to the semiconductor substrate. The temperature sensitivity of a device having such a configuration is greatly influenced by the heat of the semiconductor itself.

In the embodiment of FIG. 1, the member or sensing element 34 is provided in a bridging manner over the recess 20 and has first and second ends connected to the first surface 14 of the semiconductor. ing. In this way, the detection probe 34
When viewed from above, it has a roughly rectangular shape and consists of the p1 resistance element 16 and part of the dielectric layers 12 and 18.

In the embodiment of FIG. 2, the member 32 consists of the resistive element 16 and part of the dielectric layers 12 and 18;
The sensing strand 32 is connected to the first surface 14 of the semiconductor at only one end 36 and is cantilevered over the hinge 20. Having only one end of the sensing element 32 connected to the semiconductor body 10 allows the sensing element 32 to expand and contract in nearly all directions without substantial constraint from the semiconductor body 10. There are many advantages of glazes, including these advantages. In addition, the heat loss (leat 1 oas ) transferred through the sensing strand 32 takes place only at one end thereof, so that the sensing strand 32 is well thermally insulated.

FIG. 3 is a front cross-sectional view of a preferred embodiment comprising two detection probes 32 and 34;
Figure 3 shows various advantages 11. FIG. Regarding the 70-7 sensor of the present invention, one set of members is a preferred embodiment with several advantages. As will be explained below, automatically temperature compensate for changes in the temperature of the environment, for example by using two substantially independent components and comparing the signal from one with the signal from the other. be able to. Such a configuration reduces back ground pressure (back ground pressure) within a single detection element.
-ground voltage) is easily approximately a,
Since b can be removed, the measurement can be greatly increased by 8 degrees. Furthermore, the use of two measuring elements in a flow sensor, as will be further explained below, allows the upstream sensing element to be more sensitive than the downstream sensing element, so that it can indicate flow direction as well as velocity. can.

However, one sensing element supported above the recess 20 corresponds to the 70-sensor of the present invention. for example,
To detect the presence or absence of flow, the air turbulence signal generated by the flow sensor of one sensing element would be suitable for detecting the presence or absence of air flow. Only the alternating current component of the element resistance change due to air turbulence is amplified; the slow or direct current component of the element resistance due to changes in ambient temperature, for example, is not detected.

In the preferred embodiment shown, the f-malloy can be precisely formed by sputtering in layers only a few hundred angstroms thick, and the properties of permalloy make it possible to reduce the resistance of the grid, i.e., the resistance of the resistive element 16. Permalloy has been chosen to form the resistive element 16 because of its ability to obtain a highly sensitive and predetermined correlation between the temperatures of the element 16. For example, the detection element 32 or 34 consists of a very thin member, i.e. (29), a resistance element 16 and a dielectric layer 1.
2 and 18. When applied as a flow sensor, the air flow across the sensing element 32 or 34 cools the resistance cord 16 in a predetermined relationship with the speed of the air flow, causing a change in resistance and reducing the flow of air. would be able to measure.

In the embodiment shown, sensing cords 32 and 34 are typically on the order of 0.8 to 1.2 microns thick.

This thickness includes resistive element 16, which is typically on the order of 800 angstroms thick, and dielectric layers 12 and 18, each typically on the order of several thousand angstroms thick.

Recess 20, which typically ranges in depth from 0.001 to 0.010 inches, allows resistive element 16 to be sufficiently
This very thin and low sensitivity configuration, along with the fact that it is insulated from the zero substrate, allows the sensing element to perform extremely sensitive flow velocity measurements.

As previously mentioned, the preferred embodiment of resistive element 16 is comprised of a permalloy grid (30) as shown in FIG. The lead portion 24 is f-malloy. This is because additional processes can be eliminated. That is, making the lead portion 24 from other materials requires additional processes. The permalloy lead part 24 becomes slightly hot, but the lead part
10, 11, 12 and 13, the leads are relatively wide and conduct heat substantially to the substrate of the semiconductor 10, and the leads 24 are relatively wide, as shown in FIGS. Heating is relatively small.

As previously mentioned, there are advantages in a flow transducer consisting of first and second resistive elements as illustrated in FIG. An embodiment of such a configuration, combined with a circuit such as that illustrated in Figure 5, provides a highly sensitive flow transducer that is independent of ambient temperature by eliminating background signals and providing a direct measurement signal. Obtainable.

Explanation of the operation of the embodiment of the sensor illustrated in FIG.
For purposes of explanation of the circuits illustrated in the figures, the resistive elements in these figures are designated 16A and 16B. Each resistance element 16A and 16B consists of a resistance element 16. Resistive elements 16A and 16B are at least substantially identical and are usually matched together, but need not be matched.
I don't.

A major advantage of the present invention is that the circuit shown in FIG.
It can be integrated directly onto the substrate of the semiconductor 10 (hF); in this way, a complete detection device can be obtained on a single chip by means of a patch process.

The circuit shown in FIG. 5 has, for example, three differential amplifiers each consisting of TLO87. As shown, each of the two amplifiers 50 and 52 has a feedback loose (
It has a resistance cable 16A or 16B connected in parallel to the feedback loop (feedback 1oop). Resistance element 16
A connects the amplifier 500 output 5 via its lead 24.
4 and a negative input 59. Resistive element 16B similarly connects output 56 and negative input 58 of J arm spanner 52 via its lead portion 24.
connected between.

Negative input 58 to amplifier 52 is connected via resistor 64 to potentiometer 62's Wyno J? -55.

Negative input 59 to amplifier 50 is connected to wiper 66 via resistor 70. Positive cuffs 2 and 74 of amplifiers 50 and 52 are connected to ground or reference potential 76, respectively.
It is connected to the.

Output 56 of amplifier 52 is connected to amplifier 80 via resistor 82.
The output 54 of the amplifier 50 is connected to the negative input of the resistor 8
6 to the positive input of an amplifier 80. A positive input 84 of amplifier 80 is connected to ground or reference potential 76 via a resistor 88 . The resistor 90 is the amplifier 80
0 output 92 and the purchase cuff 8.

The first terminal 94 of the potentiometer 62 has a voltage of +15VDC.
Also, the second terminal 96 of potentiometer 62 is provided for connection to a negative power supply, such as -15 VDC. Potentiometer 62 provides a means for selecting a predetermined potential (33) anywhere between the glass and negative voltages of the power supply.

In operation, the illustrated circuit generates a voltage between output 92 and ground or reference potential 760 that has a predetermined relationship to fluid velocity across sensing element 32 or 34 from resistive elements 16A and 16B.

Resistance elements 16A and 16B are connected to amplifier 50.
and 52 feedback loops. Each operational amplifier 50 and 52 maintains a constant flow rate during its feedback loop. Thus, the current through each resistive element 16A and 16B is independent of the resistance of that resistive element. In order to maintain a constant current in its feedback loop, each operational amplifier effectively changes its output voltage in response to changes in the resistance of resistive element 16A or 16B. As previously described, each i9-Malloy resistance cord 16A or 16
The resistance value of B changes in a predetermined relationship with the temperature of the resistance element. Thus, the voltage output of each (34) operational amplifier 50 and 52 has a predetermined relationship with the temperature of its associated resistive element element.

Operational amplifier 80 amplifies the difference between the voltage outputs of operational amplifier 50 and operational amplifier 52, and the voltage at output 92 of operational amplifier 80 is proportional to the voltage difference between the output voltages of operational amplifier 50 and operational amplifier 52. Therefore, the voltage at output 92 is
It has a predetermined relationship with the temperature difference between the resistance cord 16A and the resistance element 16B. The temperature difference between resistive elements 16A and 16B has a predetermined relationship with the fluid velocity across the sensing element. Therefore, amplifier 8
The zero output 92 voltage will have a predetermined relationship to the fluid velocity across resistive elements 16A and 16B.

First, the detection element consisting of the first member, ie, the resistance element 16A, is turned on, and then the second member, ie, the detection element 16A is turned on.
The fluid flow across the sensing element 6B will cause the resistive element 16A to be cooler than the resistive cord 16B. This is because the flow of fluid applied to the resistive element 16A carries away heat from the resistive element 16A, and 4=J of the resistive element 16B.
This is because it brings heat to those who are close to it. Assuming that the 1-to-1 supply voltage at W/F-66 is positive, the output voltage of amplifier 52 will also be greater than the output voltage of amplifier 50. This difference is multiplied by amplifier 80 and the output voltage at output 92 exhibits a predetermined relationship with the fluid velocity. As previously mentioned, the output voltage at output 92 can also provide a directional indication. For example, if resistive elements 16A and 16B are arranged along the flow within a duct, the two sensing element sensors of the present invention can be used to detect the direction of fluid flow as well as the flow rate. This is because, as mentioned above, the upstream detection element will be more sensitive than the downstream detection element.

As described above, the circuit shown in FIG. 5 operates resistive cords 16A and 16B in a constant '8L flow mode. Also,
In other circuits, resistor cables 16A and 16B1 or
Other sensors of the present invention may have circuits that operate in constant voltage mode, constant altitude or redundant resistance mode, or low-resistance mode.

Next, an example in which the present invention is used as a humidity sensor will be described. In this application, the sensor of the invention uses a surface absorption gradient 91
(5 surface advertising effect
cts) and optical eff
It is possible to measure the water vapor concentration or relative humidity of the atmosphere without undergoing any ects), is compatible with the integration of signal processing circuits, and can be realized on a single semiconductor chip at a very low cost.

The humidity sensor of the present invention is based on the principle that the thermal conductivity of air changes as the water vapor concentration changes. Here, the water vapor concentration is defined as the ratio of the number of water vapor molecules per unit volume to the number of dry air molecules per unit volume. This concentration is often determined by the average molecular weight (ave) of dry air.
The ratio of the molecular weight of water to the molecular weight
molar humidity (humidity)
humidity).

(37) Therefore, although not shown, the humidity sensor of the present invention has a multiplier suitable for molar humidity measurement. -IDt] Gives one mole of water to the concubine, which is converted into a ratio of 7 through wr.

It is also of interest to convert the molar humidity measurements to a constant value of 61 relative degrees. For such a transformation, d
It is necessary to measure the ambient temperature and temperature, and standard humidity chart data (5 standard psychometric c
hartdata), a corresponding automatic adjustment must be made. Some altitude effects due to air mixing density changes also result in fusion in the conversion to relative humidity.

This is because, for a given mole fraction of water vapor, as measured by thermal conductivity, the partial pressure of water vapor will change with altitude.

Therefore, for the most accurate measurement of relative humidity, the conversion is
altitude-dependent factor
factor). Such conversion would be performed by circuitry not shown.

Environmental control applications require devices that read out the enthalpy of mixed air with respect to the enthalpy at some low reference temperature and zero humidity. Enthalpy varies linearly with temperature - in foot molar humidity, and - to the extent that excludes icing and condensation #4 - changes linearly with molar humidity in foot temperature. Determination of enthalpy can be obtained by circuit from molar humidity definition and mixed air temperature. The circuit, not shown, produces a readout offset for the dry air proportional to the difference between the mixing temperature and the reference temperature and converts the molar humidity output to an enthalpy scale.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of application of the present invention to a humidity sensor will be explained below in detail by way of an embodiment using the drawings.

In its simple form, the humidity sensor of the invention comprises a substrate 100
a semiconductor substrate having a feature 102 etched or otherwise formed in a first surface 104 of the semiconductor body, further comprising a sensing element 10 such as shown at 106;
It has 6. The sensing element 106 may be bridge-shaped over the recess 102 in the same manner as the sensing confection 34 of FIG. 1, or cantilever-shaped as shown in FIGS. 2 and 6. It is probably shaped like a cantilevered rope. Member or detection element 10
6 usually has a resistive element designated by 108 and has a predetermined shape placed above the corner 102 at an IJJT constant distance.

Sensing element 106 is connected to first surface 104 at at least one location, such as shown at location 110 . The depression 102 defines an open valley in the first surface around at least a portion of the predetermined configuration of the member or sensing element 106 .

When the resistive element 108 is heated by being supplied with an electric current, the predetermined relationship between the resistance value of the resistive element 108 and the hot fat is broken.

The humidity sensor of the present invention further prevents the flow of air across the detection element 106 by activating the flow prevention means 116 as shown in FIG.
8 is blocking cooling.

The flow stop means 116 has an opening 118 to equalize the humidity level of the detection confectionery 106 and the semiconductor body 100 with the humidity level of the surrounding environment. Additionally, to prevent the sensor from being contaminated by airborne particulates,
A filter 120 is provided.

The resistor element 108 is used to provide a signal having a magnitude related to the resistance value of the resistor element 108, that is, the temperature, and the magnitude of the signal is determined by the resistance between the element 108 and the semiconductor substrate 100 via the resistance element 102. The thermal coupling (t
thermal coupling) and changes with humidity. This change in thermal coupling occurs through changes in air conductivity as well as changes in molar humidity.
As a result, humidity can be measured.

In a typical application of this humidity sensor, the chip or semiconductor body 100 has a header.
) is attached to a glass member 114 provided at 112 with epoxy. This glass member 1
14 thermally insulates the base body 100 from the protruding portion 112 of the hollow. This part (41) is not shown, but is usually used to connect a wire bonding arrangement to make an electrical connection.
It has a feedthrough.

Furthermore, this humidity sensor has a reference resistance means 122 consisting of a resistance element 124. As discussed further below, the sensor according to the invention has a thermal coefficient of resistance (thermal coefficient of resistance) over the required predetermined temperature range.
mal coefficient ofresista
nce: TCR) is almost zero. As shown in FIG. 7 and below, the row of resistive elements 126 may be connected in series with the resistive elements 124. Instead, resistor element 1 in series
26 may be connected in series with the resistive element 108. For example, the series resistive element 126 may be chromium silicide (chr).
ome 5ilicide) or nichrome (nic
hhome) element.

Furthermore, the humidity sensor of the present invention has a heater consisting of an element 128, and is adapted to control the temperature of the semiconductor substrate (42) 100 to a predetermined temperature. Element 128 comprises a resistive element, such as a permalloy element, that substantially transfers heat to the semiconductor substrate.

Like resistor element 108, resistor cord 124 is comprised of a permalloy grid as shown in FIG. In this way, the resistive element 124 not only serves as a reference resistance for the resistive wire 108, but also as a temperature measuring means for the resistive element 124 or the temperature-controlled semiconductor body 100. Permalloy has a predetermined relationship between depth and resistance. In this way, the semiconductor body 100 can be maintained at a predetermined high temperature by adjusting the current flowing through the resistive element 128 and monitoring the temperature of the base body 100 with the resistive element 124.

As shown, resistive elements 108, 124, 126, and 128 are made of silicon (5ilicon n1tr).
The first layer 127 is sandwiched between two dielectric layers such as ide) and covers at least a portion of the first surface 104.

If the semiconductor substrate 100 has a 9-malloy resistive element 124 that conducts substantially 124 is substantially the semiconductor substrate 100
Since the resistance value of resistive element 124 does not substantially change with changes in humidity. Thus, the signal from resistive element 124 is canceled by the signal from resistive element 108, effectively reducing the resulting signal which would have a predetermined value under the conditions of the predetermined ratio. It will be supplied to A circuit such as that shown in FIG. 5 is used to accomplish this purpose, replacing resistive elements 16A and 16B of FIG. 5 with resistive element 108 of the humidity sensor.
And replace 124 with 1a, and replace the resistance wire 126 with an appropriate resistance element 108''!

or 124 in series.

- The temperature vs. resistance curve of the mother-Malloy element is non-linear.

The IM degree vs. resistance curve of resistive element 108 will have a first predetermined slope when operating at a first predetermined operating temperature. For example, normally the resistance cord 12
A second predetermined temperature such as an automatic rM degree adjusted temperature of the tip or substrate 100 measured by
In a storm, the resistance value of resistor value 124 is established such that the temperature versus resistance curve of resistor cord 124 has a slope that approximately coincides with the predetermined slope of resistor cord 108 at its operating temperature. Ru. The overall effective resistance of resistive wire 108 or 124 is adjusted by adding resistive element 126 in series with either resistive element 108 or 124, in this example resistive element 124, as appropriate. . and,
The movable resistance cord 126 can be operated over the required temperature range.
The thermal coefficient of resistance value is approximately zero. As a result, the total effective resistance of the reference resistance system at the second predetermined temperature is equal to the total effective resistance of the sensing element of the humidity sensor at the first predetermined temperature. It will be made to be.

In this way, the effective resistance values of the reference resistance system element and the humidity detection element are approximately equal, and the signals passing through these two elements (45) have a sum of signals that is approximately zero at a predetermined humidity. It is canceled out like this. Again, this can be achieved by a circuit such as that shown in FIG.

Next, an example in which the present invention is applied as a combustible gas sensor will be described. As mentioned above, the present invention can be applied as a sensor for detecting flammable gas. One embodiment of the combustible gas sensor of the present invention, as shown in FIG. 9, is similar to the flow sensor shown in FIG. 3, except that the reaction member 130 is thermally coupled to one of the resistive elements. very similar. When warmed in the presence of flammable gas and oxygen, reaction member 130 will indicate the presence of flammable gas. In addition, flow stop means, such as flow stop means 116 used in humidity sensors, are also used to substantially prevent air flow across the first and second sensing elements shown in the embodiment.

In FIG. 9, in contrast, the member 130 is the detection element 140.
The resistive element 142 is thermally coupled to the resistive element 142 inside the resistive element 142 . In one preferred embodiment of the combustible gas sensor of the present invention, the reaction member 130 is warmed by a resistive element 142, typically made of iron oxide, for example.

Catalytic reactivity of platinum or palladium
-tically active) thin film. In such embodiments, when the catalytically reactive thin film is warmed in the presence of flammable gas and oxygen, an exothermic reaction occurs resulting in a change in temperature and thus the resistance of its corresponding resistive element 142. The value changes. In this way, the change in the hot water temperature of the resistance element 142 due to the exothermic reaction indicates the presence of combustible gas and causes the resistance value of the resistance element to change.

In other preferred embodiments of the invention, the reaction member 130 includes:
For example, it is made of a metal oxide resistive element of iron oxide or tin oxide and is heated by the resistive element 142. The resistive element + of the gold &[oxide is the element 16r shown in FIG.
(It can be of similar shape.

In such embodiments, the resistance value of the metal oxide resistance element changes when heated by the resistance cord 142 in the presence of flammable gas and candy/base, thereby detecting the presence of combustible gas. The combustible gas sensor of the present invention then includes a pocket 1 having a recess 134 etched or otherwise formed in a first surface 136 of a chip or semiconductor body 132.
It has a body base.

This combustible gas sensor has a detection element 34 shown in FIG.
It has a detecting element 140 in the shape of a cantilever, that is, a cantilever beam, as in the case of the test piece 32 shown in FIG. 2. . This sensing element usually consists of a resistor f, designated by 142, consisting of a 0-Malloy grid as shown in FIG.
have a child

Sensing element 140 has a predetermined shape spaced one foot apart on recess 134 and is connected to first surface 136 in at least one location. The indentation 134 defines an opening in the first surface 136 at least a portion of the predetermined shape of the sensing element 14 ( ). In other words, the detection element 140 is the resistor element 14
2 and the semiconductor substrate 132. As mentioned above, this section 44-1 element 140 includes a reaction member 130 that is thermally coupled to a resistive element 142.

When the resistance element 142 is heated by being supplied with a current, a predetermined relationship is established between the resistance value of the resistance element 142 and the temperature.

In general, the combustible gas sensor of the present invention has a flow stopper such as the flow stopper 116 shown in FIG.
The flow stop means substantially obstructs the flow of air over the sensing element 140 and substantially prevents the resistive element 142 from being cooled by the air flow. An opening, such as the one shown in FIG. 118, allows flammable gas to enter and exit the reaction side 130.

As previously mentioned, in the first preferred embodiment of the combustible gas sensor of the present invention, the reaction member 130 typically comprises a catalytically reactive thin film. In such embodiments, when the reaction member 130 is heated by the resistive element 142 in the presence of flammable gas and oxygen, an exothermic reaction occurs resulting in a change in temperature and thus a change in the resistance value of the resistive element (49) 142. do. This change in resistance value of resistance element 142 will indicate the presence of combustible gas. In a second preferred embodiment, the reaction member 130 comprises a resistive element, typically a metal oxide. In such embodiments, when the resistive element is heated by resistive element 142 in the presence of flammable gas and oxygen, its resistance changes to detect the presence of combustible gas.

Resistive element 142 is also protected within two dielectric layers, such as silicon nitride, with first layer 144 also covering at least a portion of first surface 136. As shown, the reaction member 130 is provided on the dielectric layer 146 of the sensing element 140.

If the first preferred embodiment of the combustible gas sensor of the present invention is used, it is desirable to use a second resistive element 150, as shown by second sensing element 148. As shown, the second detection element 148
50) The second sensing element 148id is connected to the first surface 136 at at least one location and has a predetermined shape disposed at a certain distance above the corner 134. The recess 132 is formed in the first table 111u 136 by turning the predetermined shape of the detection element 148 at least 1 (1). Provide sufficient physical and thermal insulation between the

The detection element 140 and the detection element 14 are different from each other, except that the detection element 148 does not have a reaction member like the reaction part 130.
8 may be the same. The detection element 148 has a resistance element 150, and the detection element 148 has a resistive element 150, and the detection element 1
It will be used as a reference detection element that exhibits the same reaction as 40, and will perform automatic temperature correction. Additionally, the signal from the reference resistive element 150 acts to cancel the signal from the transmissive element 142, excluding the level of the pack ground signal caused by the thermal changes induced by the responsive member 130. This makes it possible to directly measure the detected signal. Substantially the same circuit as shown in FIG. 5 is used to accomplish this purpose, replacing resistive elements 142 and 150 with resistive elements 16A and 16B of FIG.

Next, an example in which the present invention is applied as a pressure sensor will be described.

As mentioned above, the present invention is suitable for use as a pressure sensor - for example, in sub-atmospheric pressure
It can be applied as a senna to measure herric pressure. Pressure sensors that cover a relatively wide dynamic range are desired.

For example, oxygen, argon,
Common industrial processes that utilize gases such as nitrogen and hydrogen often require pressure measurements as part of gross control.

Conventional thermal conductivity pressure sensors that heat tungsten in sub-atmospheric ranges have not been satisfactory. Because of the relatively low dynamic range, high power and voltage requirements: fragility, low thermal coefficient of resistance (lo
w thermal coefficent ofr
relatively low sensitivity due to the oxygen partial pressure (
However, if the amount of tungsten is increased too quickly, it will easily oxidize, resulting in a short lifespan. The pressure sensor of the present invention significantly reduces or eliminates these disadvantages.

The pressure case/thermal chamber of the present invention is also based on changes in thermal conductivity of unit gas volume. In particular, the mean free path length (mean
Since the free path lengths ) is limited, for example, by the distance between the sensing element 106 and the underlying semiconductor substrate 100 in FIG. 7, the heat transfer i (heat removal rate ) from the sensing element
and thermal conductivity decrease with decreasing gas pressure.

This leads to an increase in the temperature of the resistive element 108, assuming that the resistive element 108 is operating at a constant current.

The pressure sensor of the present invention may have the same configuration as the humidity sensor of the present invention, and will be explained using the same diagram used to explain the humidity sensor.

In its simple form, the pressure sensor of the invention comprises a substrate 100
a semiconductor body having a recess 102 etched or otherwise formed in a first surface 104 of the semiconductor body and further having a sensing element 106 as shown at 106 (53). The sensing element 106 has a recess 1 similar to the sensing element 34 of FIG.
02 or cantilevered as shown in FIGS. 2 and 6. The member or sensing tether 106 generally has a resistive element generally designated 108 and has a predetermined shape positioned above the nozzle 102 at a predetermined distance. The detection element 106 is located at position 1
It is connected to the first surface 104 at at least one location, such as indicated at 10 . The recess 102 forms an opening in the first surface by at least a portion of the predetermined configuration of the member or sensing element 106 .

Resistive element 108 has a predetermined relationship between the resistance value of resistive element 108 and the temperature when the resistive element 108 is heated by supplying current.

The pressure sensor of the present invention further includes a flow prevention means 116 as shown in FIG. 8, which substantially prevents the flow of air across the detection cord 106 and prevents the resistance element 108 from being cooled by the air flow (54). It's closed.

Is this 1. The first means 116 has a corpse port 118 to equalize the pressure level of the detection element 106 and the semiconductor substrate 100 to the pressure level (!-) of the surrounding environment. A filter 120 is provided to prevent this from occurring.

The resistance element 108b1 is used to apply a signal having a magnitude related to the resistance value and temperature of the resistance element 108, and the thickness of the signal is determined by the resistance element 108b1 and the semiconductor R The thermal coupling that changes between the bodies 100 (
thermal coupling) changes with the pressure below atmospheric pressure V. This change in thermal coupling occurs through a change in the conductivity of nitrogen with a change in pressure, and as a result, the pressure can be determined.

In a typical application of this pressure sensor, the chip or semiconductor body 100 has a protruding portion (header).
)] is provided on the glass part side 114 provided in 12 with epoxy. This glass member 1
14 thermally insulates the base 100 from the protruding portion 112. This protruding portion is typically provided with a feedthread hole (not shown) for connecting the wire landing configuration to make an electrical connection.
roughs).

More importantly, this pressure sensor uses a reference resistance means 122 consisting of a resistance element 124. As mentioned in connection with the humidity sensor of the invention, the pressure sensor of the invention has a thermal coefficient of resistance over the required predetermined temperature range.
It has a series resistance element 126 whose resistance (TCR) is approximately zero.

As shown in FIG. 7 and below, a series resistive element 126
may be connected in series with the resistive element 124. Alternatively, series resistive element 126 may be connected in series with resistive element 108. For example, series resistive element 126 may be comprised of a chrome silicide or nichrome element.

Furthermore, the pressure sensor of the present invention has a heater consisting of an element 128, and is adapted to keep the temperature of the semiconductor substrate 100 at a predetermined temperature. 128 consists of a resistive element, such as a permalloy element, which substantially transfers heat to the semiconductor substrate.

Like resistive element 108, resistive element 24 consists of a permalloy grid as shown in FIG. In this way, the resistance element 124 not only serves as a reference resistance for the resistance element 108, but also serves as a temperature measuring means for the resistance element 124 or the semiconductor substrate 100 whose temperature is automatically controlled. . Permalloy has a predetermined relationship between temperature and resistance. In this way, the semiconductor body 100 can be maintained at a predetermined high temperature by adjusting the current flowing through the resistive element 128 and monitoring the temperature of the base body 100 with the resistive element 124.

As shown, resistive elements 108, 124, 126 and 128 are made of silicon nitride (silicon n1tr).
Sandwiched between two dielectric layers such as ide ) (57), the first layer 127 covers at least a portion of the first surface 104 .

By having a Themalloy resistive element 124 that substantially transfers heat to the semiconductor substrate, the temperature of the resistive element 124 is substantially regulated by the temperature of the semiconductor body. Additionally, since resistive element 124 is substantially thermally coupled to semiconductor body 100, resistive element 124
The resistance value tends to change substantially with changes in pressure.

Therefore, the signal from resistive element 124 is transmitted to resistive element 1
08, effectively providing a resulting signal that would cure a predetermined value at one of the predetermined pressure conditions. A circuit such as that shown in FIG. 5 is used to achieve this purpose;
The resistive elements 16A and 16B shown in the figure would be replaced with the resistive elements 108 and 124 of the pressure sensor, and the resistive element 126 would be placed in series with either resistive element 108 or 124, as appropriate.

・The temperature vs. resistance value curve of the Malloy element is non-destructive (58
) Ruru. The temperature versus resistance curve of resistive element 108 will have a first predetermined slope when operating at a first predetermined operating temperature. At a second predetermined temperature, such as the temperature of the chip or substrate 100 that is normally measured by the resistive element 124, the resistance value of the resistive value 124 is determined by the temperature of the resistive element 124. The resistance value open &l is established to have a slope that approximately matches the predetermined slope of the resistive element 108 at its operating temperature. The overall effective resistance of resistive element 108 or 124 is adjusted by adding resistive element 126 in series with either resistive element 108t or 124, in this example resistive element 124, as appropriate. . The series resistive element 126 then operates over the required temperature range.
The thermal coefficient of resistance value is approximately zero. As a result, the total effective resistance of the reference resistance element at the second predetermined temperature is equal to the total effective resistance of the sensing element of the pressure sensor at the first predetermined temperature. It will be made like this. In this way, the effective resistance value of the reference resistance element and the pressure sensing element is 11 l'r
e, the signals passing through these two elements cancel out at a predetermined pressure such that the 11th of the signal is approximately zero. Again, this can be accomplished with a circuit as shown in FIG.

Although the pressure sensor of the present invention has been described as sensitive to changes in humidity levels, this is not a problem in normal applications. This is because, over the usage range of the pressure sensor of the present invention, the response to pressure changes is greater than the response to humidity changes.

First, when considering the phenomenon related to the sensor of the present invention, when the pressure of the gas becomes low, that is, the density of the gas is low, heat should be transferred from the heated part side that cures the resistance element. It is thought that the number of molecules is smaller and more frequent. When a constant current is passed through the resistance element, if there are fewer molecules, the metal will become hotter and hotter as the pressure decreases. However, in such a case,
The amount of heat escaping from the sensing element is Does not change appreciably with changes in pressure. For example, a pressure change of 10 cents (/'e-cents) reduces the gas density by a corresponding amount;
The mean free path and, in fact, the total path length of any category (
allpath lengths) is increased to the exact same amount, for example 10 inches, to compensate. Thus, for pressures when the mean free path length is short compared to the distance between the detection element and the semiconductor substrate, molecules stop when they collide, and there are fewer molecules present. Since the molecule advances 10 times without being stopped, it can be approximated that the amount of heat transferred from the detection element is the same. This is a very accurate dependent correction factor (61) only when the mean free path length of the gas molecules is short compared to the lIJ+ distance between the sensing element and the semiconductor substrate.

As described above, the pressure sensor of the present invention will not normally feel pressure near normal atmospheric pressure, for example, in the range of 1 atm to 0.1 atm.

In view of a particular preferred embodiment, permalloy resistive elements, which, in combination with microstructures, serve as heaters and temperature sensors, such as those mentioned above, can be used to detect air flow, humidity, pressure, combustible gases and other gaseous It can be seen as a holistic invention that provides the basics for detecting objects that undergo many physical changes, such as physical objects. In fact, any physical extenuant that changes in a material composition in such a way as to cause a temperature change can, in principle, be detected by a sensor based on a structure such as the one shown.

Further, the member or detection element may be an electrostatic element as shown, for example.
ment) and a thermal-to-electrlc element for detection purposes.
an electrothermal transducing element (olectrlc-to-the) for providing electromagnetic radiation (62) or otherwise serving as a source of thermal energy;
rmalelement). Of course, such generic elements are not limited to having permalloy resistive elements. This is because a suitable thermoelectric or electrostatic element is sufficient for the number of examples. Another example of a sensing element is a single crystal film of zinc oxide (
zinc oxide mono-crystalli
nefilm), thin film thermocouple coupling (thin film)
thermocouplejunctlon'),
pyroelectric materials, such as semiconductor material thermistor films;
It also includes other non-permalloy metal films with suitable temperature coefficients of resistance.

Accordingly, the invention will now be described with reference to the foregoing specific examples and general descriptions, and with reference to the structures shown in FIGS. 1-4. The present invention includes a semiconductor body 10 having a recess 20 etched or otherwise formed in a first surface of the body. Furthermore, the present invention provides a member having a thermoelectric or electrostatic element, ie, a sensing element 32 or 34, indicated by the reference numeral 16, and the sensing element is provided at a predetermined distance above the depression 20. The first surface 14 is connected to the first surface 14 in at least one location in a predetermined structure. The indentation forms an opening in the first surface by at least a portion of the predetermined configuration of the member, ie, the detection element. The recess provides sufficient physical and thermal insulation between the thermoelectric or electrostatic element and the semiconductor substrate.

Such integrated semiconductor devices can be manufactured through a patch process as described below, providing sufficient physical and thermal isolation space between the thermoelectric or electrostatic elements and the semiconductor substrate.

The manufacture of such a device according to the invention is based on the crystalline structure of the substrate.
orientation
)′! The method includes the steps of: providing a semiconductor body having a first surface to be treated; and providing a layer of material for forming a component or sensing element on the first surface. The manufacturing method of the present invention further comprises the step of exposing at least a predetermined region of the first surface,
The area of the exposed surface is arranged in a predetermined configuration such that when the recess is subsequently provided, it will be placed partially over the recess at a distance of 19 feet. is directional so that undercutting a predetermined configuration by anisotropic etching will occur in a minimal amount of time.

A preferred embodiment of the present invention is to first provide a (100) silicon wafer surface 14.

Its surface 14 has a low pressure gas discharge (10Wpres+
5ure gas discharge) in a normal soup 9. Usually 300 attached by talling technique
0 angstroms is how thick the layer of silicon nitride 12 is. The next step is usually 80% nickel and 20% nickel.
An 800 angstrom layer of I9-Malloy, consisting of 800% iron, is deposited on top of the silicon nitride by sintering.

A permalloy element 22 consisting of a grid 16 and leads 24 is formed using a suitable photomask, photoragiat and a suitable etchant.

A second layer 18 of silicon nitride, typically 5000 angstroms thick, is sputtered over the entire Nokoomalloy element to protect the resistive element and its leads from oxidation. a first layer of silicon nitride 3000 angstroms thick;
Providing a second layer of silicon nitride with a thickness of 0 angstroms would result in an asymmetrical layer member or sensing element of the dielectric; however, this lack of symmetry is due to the fact that a second layer of silicon nitride with a thickness of It can be corrected by adding layers.

10, 11, 12 and 13, openings 152 are etched through the nitride to the surface of the (100) silicon to form the respective members. Although section I is illustrated here as having straight edges, such a shape may be modified, for example, to have no curved lines.

(66) Finally, anisotropic etching (a
A nigotropic etchant is used to etch away the silicon beneath the part in a controlled manner. Potassium hydroxide (KOH) and isoglobil alcohol (1sopropyl alcohol)
A mixture of is an iM etchant (5uitable e
tchant). The etched slope is formed by the (111) plane, other crystal planes that resist etching, and the bottom of the depression in the surface of the (100) plane that weakly resists etching. The bottom of the scissors is located at a distance of, for example, 0.004 inches from the member. This is usually the etching duration (du
This is done by adjusting the ration).

For example, a layer containing boron (baron-doped)
doped silicon etch, such as
5 top) may be used to control the depth of the depression, but such a stop is usually not necessary when using the present invention.

In order to undercut the part in a minimum amount of time, for example, the predetermined shape of the edge or axis of the undercut is usually set at a non-zero angle (n) with respect to the [110] axis of the silicon.
on-zero angle) 154. The invention includes providing straight member edges or axes at an angle to minimize undercut time or, in the case of bridged members, to undercut. There is. However, if the part side had a shape without the edge of the @ line, the axis could easily be square and tight, but it could be considered that the shape itself was oriented to achieve, for example, a minimum undercut time. It will be done. By angling the dowel at approximately 45 degrees, the member or sensing element will be undercut in a minimum amount of time. For example, using a 45 degree angle, a normal sized cantilever as shown above would have an etching time of about 90 minutes compared to several hours using a 0 degree orientation.
Can be undercut in minutes.

Time for the side to be undercut? In addition to minimizing r:, using a non-zero direction will result in the production of a two-ended bridge as shown in FIG.

Such a member is virtually impossible to punch with the edges of the member oriented [110]. The edge of the scoop (110
) oriented, the anisotropic etching is not appreciably undercut at the exposed (111) crystal faces along the green of the part, or at the inside corners such as 160. This is because it is waxy. As known in the prior art, cantilevered members oriented along the [110) axis etch primarily along the length of the beam from the free end of the cantilever.

Here, there is a slight undercut from the end of the cantilever beam, but there is not much. This results in undercutting from a direction including the ends of the member compared to a member made according to the invention as previously described.

Even when oriented at 45 degrees, it is possible to quickly round and smooth the support interface at the edge of the component and the semiconductor. In this way, it is possible to avoid the occurrence of stress concentration areas that occur where the two (69) and (111) planes under the insulating layer 12 collide, as shown in Figures 1 to 31J. It may be desirable in some glaze devices to connect the first and second members by means of a connecting means, ie, in a sense, to provide the first and second elements in one member. Examples of such connecting means include the connecting means shown at 156 in FIG. 10 for connecting two cantilever-shaped portion sides as shown in FIG.
There is a connecting means, designated 158 in FIG. 12, for connecting two bridging-type members as shown in FIG.

Such connection means will help maintain uniformity of the thermal conductivity between the space and the respective member and the bottom of the cavity, and will contribute to uniformity of performance in each type of device. . For similar reasons, it may be advantageous to provide two elements in one member in a p++ manner as shown in FIG.

Furthermore, there may be applications (70) in which it is desirable to connect components to the semiconductor substrate at auxiliary locations, such as location 159 shown in FIG. 10, for processing or device configuration.

Small rectangular etched holes 152 are shown at one &-continuation end of the cantilever-shaped member in FIGS. 10 and 11 and at both ends of the bridging shape in FIGS. 12 and 13. , these holes assist in undercutting or shaping the semiconductor substrate to which the component is attached. However, such a hole 1 at the end of the member
52 is not necessary for full performance of the device.

Etched holes 15 along the edge of the member as shown
2 typically has an opening width of about 0.002 to 0.005 inch for flow sensors and flammable gas sensors, and an opening width of about 0.001 inch for humidity sensors and pressure sensors. And the narrow width of the pressure sensor helps reduce the effects of gas flow.

The semiconductor bodies of FIGS. 10, 11, 12, and 13 are shown in the form of flow sensors or combustible gas sensors and are numbered 10 or 132.

For example, humidity and pressure sensors, such as those shown in FIG. 6, are similar in construction, but typically include one member and element spaced a predetermined distance apart.

FIGS. 10 to 13 show the area of one-way integration as shown in FIG. 5.

As previously mentioned, the practical effect of the invention for detecting by thermal means is that member 32'! This is achieved by providing an air gap or recess 20 below the l: or 34. Thereby, the sensing material is well thermally and physically insulated from the substrate by an air gap, typically by a corner, rectangular area of dielectric material attached at one or both ends to the silicon substrate, as shown. It means that it is supported. As previously mentioned, although rectangular members are used, in fact any other shape could be used.

In the embodiment shown, typical dimensions of member 32 or 34 are 0.005 to 0.00 inches wide, 0.010 to 0.020 inches long, and 0.8 to 1 inch thick. .2 microns (mlcrons).

A typical permalloy element, such as element 16 shown in FIG. 4, is approximately 800 angstroms thick, but typically has a thickness ranging from 800 angstroms to about 1600 angstroms. ,
A preferred composition is 80% nickel and 20% iron, with a resistance of about 1000 ohms at room temperature. Resistance values for various applications are typically eg 25
The resistance ranges from approximately 500 ohms to 2000 ohms at room temperature of about 6°C. The temperature of the permalloy element is about 400.
When the temperature is increased to .degree. C., the resistance value increases to about 3.0 times.

The width of the permalloy grid 160 lines is approximately 6 microns with a spacing of approximately 4 microns.

<The recess 20 is usually located between the member and the semiconductor substrate 10 at approximately 0.
．． There is a clearance of 0.004 inches, but this clearance is approximately 0.04 inches.
．． It can easily vary from 0.001 inches to about 0.000 inches. The typical thickness of the semiconductor body 10 or substrate is 0,000 inches. These dimensions are provided by way of example only and are not meant to be limiting.

(73) A member of typical dimensions as shown has a very small thermal volume l and thermal impedance, about 0
This results in a thermal time constant of 0.005 seconds.

Therefore, a smaller 73 thermal input results in a new thermal equilibrium with a slightly different sensing element temperature.

This difference allows for sufficient electrical output (q'e).

The strength-t
o-welght) is very good, and a two-end bridge type of the typical dimensions mentioned above has a 10,000 gr.
It can withstand mechanical shock forces better than other materials. Even single-ended structures when used as cantilevered structures can withstand 10,000 gravity shocks.

In many applications, heating a member or sensing element, such as member 32 or '34 of FIGS. There are advantages. Typical operating temperatures range from about IoO'C to 400C. With the preferred nozzle (74), input power of only a few milliwatts is achieved.
This can be achieved. Such power levels are compatible with integrated circuits provided on the same semiconductor substrate with the sensor, if desired, as previously discussed.

A typical temperature sensor in industry has an electrical impedance of 100 ohms. However, for the purposes of the present invention, such impedances have a number of disadvantages. For processing purposes, a typical 1000 ohm impedance or a 100 ohm impedance suitable for the preferred resistive element of the present invention may be used.
．． It is very difficult to obtain an impedance N degree of 1%. The typical impedance of 1000 ohms in the permalloy elements used in the present invention is due to the electromigraton phenomenon.
This is because we considered element failure due to ). Electrical transfer phenomena are physical failure mechanisms, and in permalloy they occur in the conductor due to the mass flow that occurs when the current exceeds a dangerous limit of about 10-6 amperes per square centimeter. It is something. Therefore, in order to achieve the desired operating temperature within the permalloy element 16, even if the room temperature is 25°C.
A relatively large impedance, on the order of 1000 ohms, is desirable; a high impedance allows the desired operating temperature to be achieved without exceeding dangerous current densities.

As a result, member 32 or 3, for example as previously described.
Typical dimensions of 4 are 0, 0 as reported by the prior art.
It must be sufficiently larger than the microstructures, which are 0.01 inch wide and 0.004 inch long.

The larger area of material normally required for permalloy resistor X-elements compatible with the present invention must have sufficient surface area to provide a grid of permalloy as shown at 16. The preferred 45-degree orientation of the member as described above is a process that requires the least processing time when creating a wider microstructure and when creating a bulge shape as shown in Figure 1. This is very important from a time point of view.

As mentioned above, for many possible applications,
A preferred thermoelectric conversion or electrostatic element is the permalloy resistance element described above. When sandwiched within the silicon nitride member or sensing element, the mother-Malloy element is protected from oxidation by air and can be used as a heating element up to temperatures in excess of 400°C. Such permalloy elements have resistance vs. temperature characteristics similar to Nork-like platinum, with both permalloy and platinum having a resistance of about 4000 ppm (par
Thermal coefficient of resistance (ts per million)
esistance: hereinafter abbreviated as rTcRJ). However, permalloy is superior to platinum in structure according to the present invention. Platinum is commonly used as a material for temperature sensing elements, but permalloy has a resistivity that is twice that of platinum.
It has the advantage of ti-vity). Furthermore, in thin films, platinum must be at least 3500 angstroms thick;
Ya(77) monomalloy can achieve maximum TCR in a thickness range of about 800 to 1600 angstroms. A? - Malloy has a thickness of approximately 1600 angstroms and its maximum TC
R can be achieved, but the specific resistance is double and the TCR is 1600.
800 angstroms is selected as the preferred thickness since it is only slightly less than 800 angstroms. Therefore, using permalloy elements on the order of 800 angstroms thick, platinum requires only one-eighth the surface area required for the same resistance, increasing the thermal efficiency of the sensing element, requiring less area, and Can reduce costs.

In this way, the mother-Malloy element is an efficient heater element and an efficient sensing element, and has a thermally insulated structure with respect to temperature changes in the microstructure as shown above. On top of that, the combination of both heater and detection functions in the same element allowed for low cost, small heat capacity, excellent sensitivity and fast 11,000 Hz.

In addition,)f! 1 Usually, electrified silicon of about 1 micron (
78) i4 displayed in the supporting insulating thin film? - The element for the heater and detection of the malloy provides scivation against oxidation of the thin film of the malloy, especially at high abrasions. It also allows precise dimensional control of, for example, liL, 32 or 34, due to the high resistance of silicon nitride to etching processes. In addition, the recesses 20 can be deeply etched to a depth on the order of 0001 inches to 0010 inches, for example, to control the necessary thermal conductivity.

Therefore, using the preferred embodiment of the present invention, Yermalloy can be combined with a microstructure as shown, a temperature sensor, a heater or a radiation source.
radiation 5source). Support and passivation material (paa
The use of silicon nitride as the sivating material 6 will provide the necessary etching time to obtain the desired structure. Furthermore, the directionality according to the invention undercuts in a minimum time and
The desired structure is created using an artificial etch stop.
al etch 5top). The thermoelectric or electrostatic elements are then fabricated on the integrated conductor device in a conventional manner by deep anisotropic etching to control the depth of the recess in the range of 0.001 to 0.010 inches. Greater thermal insulation can be achieved than

Although the foregoing description has been set forth in terms of preferred embodiments, it will be apparent to those skilled in the art that numerous odor variations are possible within the scope of this invention. It is therefore intended that the invention be limited only by the scope of the claims that follow. For example, although the recess indicated at 20 was created using the purposeful etching technique described above, embodiments in accordance with the present invention may include recesses formed by fL branching as described above. It is not limited to those who have.

[Brief explanation of the drawing]

1, 2 and 3 are Ur side views of preferred embodiments of the present invention. FIG. 4 is a diagram showing an embodiment of a grid of electrical resistance elements adapted to the present invention. FIG. 5 shows a sample M! which is compatible with a preferred embodiment of the sensor of the present invention. ! FIG. 3 is an example circuit diagram. FIG. 6, FIG. 7, and FIG. 8 are diagrams showing embodiments of the sensor of the present invention. FIG. 9 is a diagram showing an embodiment of the combustible gas sensor of the present invention. FIGS. 10, 11, 12, and 13 are views showing detailed microstructure embodiments and directions of the present invention. DESCRIPTION OF SYMBOLS 10... Single crystal semiconductor, 12.18... Silicon nitride, 16... Grid, 14... First surface, 20...
... Hollow, 32.34... Detection element, 24... Lead portion, 50.52.80... Amplifier, 62... Potentiometer, 122... Reference resistance means, 128...
...Element, 130...Reaction member, 114...
Glass member, 116...Flow stopper, 118...
Opening, 120... Filter, 156, 158...
Connection means. Patent Applicant: No. 1981, New York, United States (US), Patent Attorney Yoshiharu Matsushita (81)
Add 31.0262 ■October 91, 1981 off the coast of the United States (US)■310263 ■October 9, 1981■■United States (US)■3]026
4 @October 9, 1981 0■United States (US)■31034
4 ■October 9, 1981 United States (US) 03103
45: Camper John P. Sumner 71-01 Heatherton Trail, Edina, Minnesota, USA

Claims (1)

[Scope of Claims] (1) A semiconductor substrate having a depression formed on a first surface of the substrate; a member connected at at least one location to the first surface in a predetermined configuration, the rim having a member connected to the first surface at at least one location in the predetermined configuration;
between the electrostatic element and the semiconductor body by forming an opening in the first surface around the portion to provide sufficient physical and thermal insulation between the semiconductor body and the electrostatic element; A semiconductor device characterized in that it provides sufficient physical and thermal insulation space and is used as a sensor. (2. In claim (1), the semiconductor substrate has a (100) plane and a (1103 direction).
00, the first surface of the semiconductor body is substantially parallel to the (100) plane, and the predetermined configuration is oriented at a non-zero angle in the [110] direction. A semiconductor device characterized by: (3) In claim (1) or (2), wherein the member is connected to the first surface at two locations, and the pre-filled configuration is located above the recess. A semiconductor device characterized by being a bridge between (4) In claim (1), (2) or (3), the member is connected to the first,
A semiconductor device characterized in that the predetermined structure is in the form of a cantilever that is cantilevered on the second side of the recess. (5) Claims (1), (2), (3)
) or (4), the semiconductor device is patented for use as a flow sensor. (6) Percentage meter In claim (1), (2), (1), or (4), the above-mentioned member is provided with a reaction part and used as a combustible gas sensor. A semiconductor device characterized by: In claim (6), the semiconductor device is characterized in that the combustible gas sensor is covered with a flow prevention means. Section, (3)
Section. The semiconductor device according to item (4), item (5), item (6), or item (7), wherein the electrostatic element is a resistive element. (9) A semiconductor substrate having all the depressions formed on the first surface of the substrate, and a thermoelectric element having a predetermined configuration provided at a predetermined distance above the depression, a member connected at at least one location to a surface of the at least one surface of the at least one surface of the at least one of the predetermined configurations;
between the thermoelectric element and the semiconductor substrate by forming an aperture in the first optical surface with the rotation of the portion to provide a sufficient physical and thermal barrier between the semiconductor substrate and the thermoelectric element; The hemiplegia device is characterized in that it provides sufficient physical and thermal P, M information to the body and is used as a sensor. 00 In claim (9), the semiconductor substrate has a c-shaped structure having a (100) plane and a [110] direction.
The first surface of the semiconductor substrate is substantially parallel to the (100) plane, and the predetermined configuration is at a non-zero angle in the [110] direction. A semiconductor device characterized by being oriented. 0]) In claim 9 or 4, wherein the member is connected to the first surface in two positions, and the predetermined configuration is bridged over the recess. Semiconductor device with special features. 0'4 In claim (9), item (l[I-th (] η), the above-mentioned member is connected to the above-mentioned first, and the above-mentioned predetermined configuration is connected to the - A semiconductor device characterized in that it is in the form of a cantilever that is cantilevered. A semiconductor device having all the characteristics of being used as a flow sensor. ◇→ Claims (9), 00, 0υ, or 0'4, wherein the above member is provided with a reaction member, A semiconductor device characterized in that it is used as a combustible gas sensor.0li The semiconductor device according to claim α1, characterized in that the combustible gas sensor is covered with a flow stopper. Range No. (9), No. 4, No. 01. In No. (6), No. α:), No. CL→, or No. αυ, all characteristics are that the thermoelectric element is composed of a resistive element. 0η A semiconductor device having a semiconductor substrate having a depression formed on a first surface of the substrate, and first and second electrostatic elements, which are provided on the depression at a predetermined distance. a member connected to the first surface at at least one location in a predetermined configuration;
forming an opening (5) in the first surface by turning the portion to provide sufficient physical and thermal insulation between the semiconductor substrate and the first and second electrostatic elements; . A semiconductor device which is used as a sensor 9 by providing sufficient physical and thermal insulation space between the first and second electrostatic elements and the semiconductor substrate. α4 In claim 04, the member is
A first member having all the first electrostatic elements and a second member containing the second electrostatic element, the first member and the second member are each placed in a predetermined position on the recess. at least one location connected to the first surface in a predetermined configuration spaced apart from each other; A semiconductor device characterized in that an opening is formed in the first optical surface around at least a portion thereof, and the twentieth group IVi is connected to the first member. (6) The first surface of the body substrate is substantially parallel to the (100) plane. The configuration is as above (1
A semiconductor device characterized in that it is oriented at a non-zero angle in the 101 direction. (2, Claim No. 07), (18), Claim 1, or (19), wherein the member has two parts on the first surface.
The above predetermined configuration is connected in two places:
A semiconductor device having a t% characteristic of being bridged over the above-mentioned ridge. (2. In Claims (17), (18), (191) or (2(1)), the said part shrine is connected to said first and said predetermined A semiconductor device characterized in that the configuration is a cantilever shape that is cantilevered above the recess. (22, Claim 8g (17), (18th item, α()) A semiconductor device having all the features of being used as a flow sensor in Claims, Claims (20), (1), or (21). ), paragraph (20) or paragraph (21),
A semiconductor device characterized in that at least one member serves as a reaction member and is used as a combustible gas sensor. (2. Claim (23) m) The semiconductor device characterized in that the combustible gas sensor is covered with a flow prevention means. (25)%￥fClaim (17), 2) Ji (18
), No. 0, No. (20), No. (21), No. 2
The semiconductor device according to item 2), item (23), or item (24), wherein the electrostatic element is a resistive element. (26) A semiconductor substrate having a notch formed on the first cut surface of the base body, and a first and second thermoelectric element, which are provided on the notch at a predetermined distance. a member connected to the first surface at at least one location in a predetermined configuration;
the first and second thermoelectric elements by forming an opening in the first seat with a turn of the portion to provide sufficient physical and thermal insulation between the semiconductor substrate and the first and twentieth thermoelectric elements; A semiconductor device characterized in that it provides sufficient physical and thermal insulation space between the second thermoelectric element and the semiconductor substrate, and is used as a sensor. (27) %1ff - In claim (26),
The member includes a first member having the first thermoelectric element and a second member having the second thermoelectric element. at least one location on said first surface in a predetermined configuration provided at a distance of at least one of said first and said second recesses. A semiconductor device characterized in that an opening is formed in the first surface around a portion, and the first member and the second member are connected. (2. In claims (26) and (27), the semiconductor substrate has a (100) plane and a (1
10) the first surface of the semiconductor body is substantially parallel to the (ioo) plane, and the predetermined configuration is in the
110] A semiconductor device characterized in that it is oriented in a direction at a non-zero angle. (9) (2. In Claims (26), (27), or (28), the member is connected to the first bottom surface at two positions, and the member is connected to the first bottom surface at two positions, The configuration is
A semiconductor device having all the features of bridging the above-mentioned features. (30) In claim (26), (27), or (28), the member is
- a semiconductor device which is connected and characterized in that said predetermined configuration is in the form of a cantilever cantilevered over said groove; (31) Claims (26) and (27)
), (289), (29), or (30), the semiconductor device is characterized in that it is used as a flow sensor. (32) Claims (2), (2), (30) In paragraph 27), paragraph (28), paragraph (29) or paragraph (30), at least one member is provided with a reaction member, h]
A semiconductor device characterized by being used as a combustible gas sensor. (33) A semiconductor device according to claim (32), wherein the combustible gas sensor (10) is covered with a flow prevention means. (34) Claims (26) and (27),
Clause (28), Clause (29), Clause (30), Clause (31)
), (32) mt, or (33), the semiconductor device characterized in that the thermoelectric electrons include a resistive element. (35) a semiconductor substrate having a recess formed in a first optical surface of the substrate; and a resistive substrate having a predetermined relationship between resistance and temperature when heated by applying an electric current. , a member in a predetermined configuration disposed a sufficient distance above the aperture and connected to the first light surface at at least one position; and a member for air flow to the member. This can be prevented by providing a basin between the member and the semiconductor substrate, and a flow prevention means that makes the surrounding environment approximately equal, so that the upper part of the recess is at least one of the predetermined configurations. 1 between the resistive element and the semiconductor substrate by forming a full opening in the first surface around a portion to provide sufficient physical and thermal insulation between the semiconductor substrate and the resistive element; 1. A semiconductor device characterized in that it provides sufficient physical and thermal insulation space to the semiconductor device, and is used as a sensor. (36) In claim (35), the semiconductor substrate includes (100) and [110] 6iI
The first surface of the semicircular base body is substantially parallel to the (100) plane, and the predetermined configuration is in the [110] direction. (37) A-h Claim No. (35) Dust or (36) No.
), the member has two positions 1 on the first surface.
A semiconductor device, all characterized in that the pre-ordered structure is connected at the neck and bridged over the neck. (38) In claim (35), (36), or (37), the member is connected to the first, and the predetermined configuration is A semiconductor device characterized by being cantilever-shaped. (39) Claims paragraphs (35) and (36).
The semiconductor device according to item (37) or item (38), wherein the resistance element is made of a Noyer Malloy resistor. (40)% Scope of Claims Clauses (35) and (36)
A semiconductor device characterized in that it is used as a humidity sensor in item (37), item (38), or item (39). (41) Claims (35) and (36),
A semiconductor device having all the features of being used as a pressure sensor in item (37), item (38), or item (39). (42) a semiconductor substrate having a recess formed in a first body of the substrate; and a resistive element having a predetermined relationship between resistance and temperature when heated by application of an electric current; a predetermined configuration disposed a predetermined distance above the recess and connected to the first surface at at least one location; (13) a reference resistance means through which heat is transferred from the semiconductor substrate; the recess is fully opened in the first bottom surface in at least one portion of the predetermined configuration, and the recess is substantially equal in width to the semiconductor body and the resistor. By providing sufficient physical and thermal insulation between the resistive elements and the semiconductor substrate, sufficient physical and thermal insulation space is provided between the resistive element and the semiconductor substrate, and it is possible to use the resistive element as a sensor. Characteristic semiconductor devices. (43) In claim (42), the semiconductor substrate has a (1005'/IJ...) having an (ioo) curve and a (110) direction, and the first optical surface of the semiconductor substrate For example, the semiconductor device is substantially parallel to the above (100) (1), and the predetermined configuration is oriented at a non-zero angle in the [110] direction. !'F Claims (42) or (43), wherein the member is connected to the first surface at two positions, and the predetermined configuration is defined in claim (14). (45) Claim (42) or (43)
3. The semiconductor device of claim 1, wherein the member is connected to the first member, and the predetermined configuration is cantilevered over the recess. (46) Claims (42) and (43),
In paragraph (44) or (45), the semiconductor device is characterized in that the resistance element is made of a permalloy element. (47) Claims (42) and (43);
In item (44), item (45) or item (46), semiconductor device +t used as a humidity sensor. (48) Claims (42) and (43),
Item (44), ;g (45) or item (46), t% indicates that the semiconductor device is used as a pressure sensor. (49) #Claims No. (42) ] Jj, No. (
In item 43), item (44), item (45), item (46), item (47), or item (48), the semiconductor substrate is heated to a predetermined temperature. A semiconductor device characterized by having a heater for total temperature control. (50) Scope of ψf claims Clauses (42), (43), (44), (45), (46), (4)
The semiconductor device according to item 7) or item (48), wherein the reference resistance means comprises a permalloy element. (51) providing a semiconductor substrate having a predetermined direction with respect to the crystal structure of the semiconductor; providing a semiconductor substrate having a first layer r[8Y; providing a material layer constituting the member on the first surface; exposing at least one predetermined area of the first optical surface such that the predetermined configuration has an orientation; anisotropically etching said region connected to said semiconductor body at at least one location and forming an opening entirely around at least a portion of said predetermined feature in said first surface; A predetermined distance m above the depression
, -i. A method of manufacturing a semiconductor device having the above member formed in -i. (52) Feature Fl: In claim (51), the semiconductor substrate has a (100) plane and a (110) direction -
the first surface of the semiconductor body is substantially parallel to the (100) surface, and the pre-ordered configuration is A semiconductor device characterized in that it is oriented at a non-zero angle in the (110) direction.
In Clause 1, the predetermined configuration has substantially congenital edges oriented at zero angles, and -f. (54) Bamboo rF ice range No. (51)
), the predetermined configuration is oriented at a non-zero angle II! Method for manufacturing a semiconductor device characterized by having Ill (55) Claim (53) or (54)
%, the non-zero angle is approximately 45 degrees.
Characteristic #-Rumor bowl device manufacturing method. (17) (56) providing a semiconductor substrate having a first interface having all predetermined directions with respect to the crystal structure of the semiconductor; providing a material layer constituting the member on the first surface; at least one predetermined first and second region'(f-m) of said first surface such that said predetermined configuration has a direction; anisotropically etching the exposed area to undercut a portion of the semiconductor body, the at least a portion of the predetermined configuration being connected to the semiconductor substrate at two locations and at the first interface; A method for manufacturing a semiconductor device having the member formed at a predetermined distance above the recess having an opening around the entire periphery of the semiconductor substrate. is a (100f'i IJ rice amount ~ shi, upper ropi semiconductor group (
18) The first surface of the body is substantially parallel to the (100) plane, and the predetermined configuration is in the [110]
A semiconductor device characterized in that it is oriented at a non-zero angle in a direction. (58) Claim (56) or (57)
3. The method of manufacturing a semiconductor device according to paragraph 1, wherein the predetermined configuration has substantially straight edges oriented at a non-zero angle. (59) Scope of claim @ (56) or (57)
), wherein the predetermined configuration has an axis oriented at a non-zero angle. (60]% Claims paragraph (58) or (59)
2. The method of manufacturing a semiconductor device according to paragraph 1, wherein the non-zero angle is approximately 45 degrees.