KR101051348B1 - Capacitive pressure sensor and its manufacturing method - Google Patents

Abstract

The present invention provides a method for manufacturing a semiconductor device, the method including: depositing a first silicon carbide and a second silicon carbide on a first silicon wafer and a second silicon wafer, respectively; A first and second step of depositing a low temperature silicon oxide film on the first silicon carbide; A first step 1-3 of forming a first PSG film and a second PSG film by depositing PSG on top of the low temperature silicon oxide film and the second silicon carbide to improve adhesion between the second silicon carbide and the low temperature silicon oxide film; Etching a groove having a predetermined depth on one side of the upper surface of the first PSG film and the low temperature silicon oxide film; A step 1-5 of bonding the first PSG film and the second PSG film to face each other; And a first step 1-6 of etching the second silicon wafer; and a method of manufacturing a capacitive high temperature pressure sensor and a capacitive high temperature pressure sensor manufactured thereby are realized.

Capacitive Type, High Temperature Pressure Sensor, Silicon Carbide, Low Temperature Silicon Oxide, Multiple Grooves, Etch

Description

Capacitive High Temperature Pressure Sensor and Fabrication Method Thereof}

The present invention relates to a capacitive high temperature pressure sensor and a manufacturing method thereof, and more particularly, using silicon carbide as an upper electrode and a lower electrode, and using a low temperature silicon oxide film or a silicon oxide film as an insulating layer at a high temperature of 250 ° C or higher. The present invention relates to a capacitive high temperature pressure sensor having excellent characteristics and stable and a manufacturing method thereof.

Currently, research on semiconductor pressure sensors using micromachining technology, which is a microfabrication technology using a semiconductor manufacturing process, is being actively conducted. The semiconductor pressure sensor microfabricated by micromachining technology is widely used in various fields such as automotive systems, industrial control, environmental monitoring, and biomedical diagnostics.

Pressure sensor is a device for measuring absolute pressure or gauge pressure, and according to the sensing principle, strain gauge type metal pressure sensor, piezoresistive pressure sensor, piezoelectric pressure sensor, MOSFET type, piezojunction type, optical fiber pressure It is divided into sensor and capacitive pressure sensor. Of the above-described pressure sensors, except for the metal type pressure sensor, the other ones are manufactured using micromachining technology using silicon, which is a semiconductor material.

The capacitive pressure sensor forms a parallel plate capacitor between the silicon thin film diaphragm and the support, and according to the deflection (deformation of the membrane) of the silicon thin film diaphragm according to the pressure applied from the outside The principle of changing the capacitance value by changing the distance between two electrodes is used.

These capacitive pressure sensors are divided into absolute and gauge pressure types. Absolute pressure type is a pressure sensor that can measure the external pressure based on a constant pressure in the reference pressure chamber by making the diaphragm in a sealed condition. This absolute type has the advantage that it is completely blocked from the outside and is not influenced by surrounding materials, but the non-linearity is caused by the compression of the air inside the reference pressure chamber, and as the temperature increases, the offset and temperature drift are caused by the expansion of the air in the reference pressure chamber. There is a problem that occurs.

On the other hand, the gauge pressure type is a pressure sensor that can measure the pressure based on atmospheric pressure because the reference pressure chamber is opened by drilling a hole in the glass part, so it is open to the outside and is easily affected by surrounding materials, but the inside of the reference pressure chamber is sealed. Since it is not in a state, there is no influence on internal air compression or expansion.

The capacitive pressure sensor that detects the capacitance between two electrodes using the deflection of the diaphragm (deformation of the membrane) has tens to hundreds of times more sensitivity (higher sensitivity) than the piezoresistive pressure sensor. . In addition, it has the advantage of excellent stability (lower temperature coefficient, stronger structure) and lower power consumption (lower power consumption).

As such, the structure of the capacitive pressure sensor has many applications because it has better sensitivity and temperature characteristics than the piezoresistive pressure sensor. When the piezoresistive pressure sensor is used at a high temperature, it is difficult to use because the piezoresistive characteristic disappears due to diffusion phenomenon at 200 ° C or higher. In the case of the capacitive type, since the distance between two electrodes, that is, the structure is influenced only by the structure, minimizing the change according to the temperature of the membrane does not cause a problem in the application. However, in the conventional capacitive pressure sensor, the capacitance is inversely proportional to the distance between the two electrodes, and when the external pressure is applied, the membrane is bent in a flat state rather than moving downward, thereby linearizing the change in capacitance with respect to pressure. There is a problem that it is difficult to have (linearity). That is, there is a problem in that the linearity of the output to the input is not good, making the sensor compensation difficult, so that the available pressure range is narrow, so that the actual use is restricted.

Accordingly, the present invention has been made to solve the above problems, using a doped silicon carbide having excellent characteristics at a high temperature of more than 250 ℃ as the upper electrode and the lower electrode, and the silicon oxide film or low temperature (room temperature, room temperature) as an insulating layer It is an object of the present invention to provide a capacitive high temperature pressure sensor having excellent characteristics and stable at high temperatures of 250 ° C. or more using a silicon oxide film and a method of manufacturing the same.

An object of the present invention as described above is the first step of depositing the first silicon carbide and the second silicon carbide on the first silicon wafer and the second silicon wafer, respectively; A first and second step of depositing a low temperature silicon oxide film on the first silicon carbide; A first step 1-3 of forming a first PSG film and a second PSG film by depositing PSG on top of the low temperature silicon oxide film and the second silicon carbide to improve adhesion between the second silicon carbide and the low temperature silicon oxide film; Etching a groove having a predetermined depth on one side of the upper surface of the first PSG film and the low temperature silicon oxide film; A step 1-5 of bonding the first PSG film and the second PSG film to face each other; And a first step 1-6 of etching the second silicon wafer.

In this case, the first step 1-1 deposits the first silicon carbide and the second silicon carbide by low pressure chemical vapor deposition.

Also, in the step 1-1, the upper surface of the first silicon carbide is polished to facilitate the deposition of the low temperature silicon oxide film.

In addition, in the step 1-1, the first silicon carbide and the second silicon carbide are deposited to a thickness of 2500 nm to 3500 nm.

In addition, in the first and second steps, a low temperature silicon oxide film is deposited to a thickness of 2000 nm to 3000 nm.

In addition, in the first to third steps, the first PSG film and the second PSG film are deposited to a thickness of 80 nm to 120 nm.

In addition, in the first to third steps, the upper surfaces of the first PSG film and the second PSG film are polished to improve the adhesion between the first PSG film and the second PSG film.

In addition, steps 1-4 form a plurality of grooves.

In addition, the first to fourth steps may form a groove using at least one of exposure etching and wet etching.

In addition, the first step 1-5 is thermocompression bonding.

In addition, steps 1-6 wet-etch the second silicon wafer TMAH.

In another category, an object of the present invention is to provide a method of depositing a first silicon carbide and a second silicon carbide on a first silicon wafer and a second silicon wafer, respectively; A step 2-2 of depositing a first silicon oxide film and a second silicon oxide film on the first silicon carbide and the second silicon carbide, respectively; Etching to form a groove having a predetermined depth on an upper side of the first silicon oxide layer; A second to fourth step of bonding the first silicon oxide film and the second silicon oxide film to face each other; And a second step 2-5 of etching the second silicon wafer, which may be achieved by a method of manufacturing a capacitive high temperature pressure sensor.

In this case, step 2-1 deposits the first silicon carbide and the second silicon carbide by low pressure chemical vapor deposition.

Also, in the step 2-1, the upper surfaces of the first silicon carbide and the second silicon carbide are polished to facilitate the deposition of the first silicon oxide film and the second silicon oxide film.

In addition, the first silicon carbide and the second silicon carbide in the step 2-1 is deposited to a thickness of 2500nm to 3500nm.

In addition, in step 2-2, the upper surface is chemical-mechanical polished (CMP) for smooth adhesion of the first silicon oxide film and the second silicon oxide film.

In addition, in step 2-2, the first silicon dioxide is deposited to a thickness of 2000 nm to 3000 nm, and the second silicon oxide film is deposited to a thickness of 150 nm to 250 nm.

In addition, in step 2-3, a plurality of the grooves are formed.

In addition, in step 2-3, a groove is formed using at least one of exposure etching and wet etching.

In addition, the second step 2-4 is thermocompression bonding. At this time, thermocompression bonding is carried out at a temperature of 300 ° C to 400 ° C under vacuum conditions of 10 ^-5 mmHg to 10 ^-7 mmHg.

In addition, steps 2-5 wet TMAH the second silicon wafer.

In another category, the object of the present invention can be achieved by a capacitive high temperature pressure sensor, which is produced by the above-described method.

According to the present invention, as the area of the capacitive pressure sensor is changed by external pressure, the output is linearly changed according to the input.

In addition, using silicon carbide as an electrode, the groove formed in the insulating layer is formed of a plurality of grooves arranged in a lattice shape, there is an effect that can obtain a strong durability that is not easily broken even under a strong pressure of 100MPa.

In addition, there is an effect that can adjust the pressure sensitivity and range by adjusting the thickness, diameter and pitch of the plurality of grooves.

In addition, since it is manufactured using high temperature and high pressure, there is an excellent and stable effect even at a high temperature of room temperature to 500 ℃.

In addition, since the etching is easier than the conventional capacitive pressure sensor, the manufacturing is simple. For this reason, the manufacturing cost is reduced.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention.

<Method of manufacturing capacitive high temperature pressure sensor>

(First embodiment)

1 is a cross-sectional view showing a first step according to the first embodiment of the present invention. As shown in FIG. 1, a first silicon wafer 110 and a second silicon wafer 210 are prepared. Such a silicon wafer has a square or rectangular plate shape having a length of 3 mm to 5 mm in width and length, respectively. The first silicon carbide (SiC: 120) for use as the lower electrode on the first silicon wafer 110 and the second silicon wafer 210, respectively, and the second silicon carbide for use as the upper electrode ( 220 is deposited (S110). Silicon carbide is an excellent material that hardly deforms at high temperatures, and can be used even at high temperatures when it is deposited to a certain thickness to minimize membrane deformation due to temperature change. Therefore, the first silicon carbide 120 and the second silicon carbide 220 are deposited by a low pressure chemical vapor deposition (LPCVD) to a thickness of 2500nm to 3500nm, preferably 3000nm. If less than 2500 nm, there may occur a problem that the characteristic changes at a high temperature, and if it exceeds 3500 nm, the sensor 10 may be insensitive. At this time, the first silicon carbide 120 polishes the surface for the smooth deposition of the low temperature silicon oxide (LTO: Low Temperature SiO ₂ ) (130) after the deposition. Silicon carbide used here has a stable physical properties even at 500 ℃ can be used stably even at a high temperature of more than 250 ℃.

2 is a cross-sectional view showing a second step according to the first embodiment of the present invention. As shown in FIG. 2, a low temperature silicon oxide film 130 as an insulating layer is deposited on the first silicon carbide 120 (S120). At this time, the low temperature silicon oxide film 130 is adjusted so that the electrode is separated and the signal is detected even when the membrane is in contact with the driving. The low temperature silicon oxide film 130 is preferably deposited at a thickness of 2000 nm to 3000 nm, preferably at a thickness of 2400 nm. If the low-temperature silicon oxide film 130 is less than 2000nm thickness can be a sensitive sensor, but the range is reduced, if the thickness exceeds 3000nm because the sensor becomes wider but the sensor is insensitive to the thickness It can be used by changing suitably according to a use mode.

3 is a cross-sectional view showing a third step according to the first embodiment of the present invention. As shown in FIG. 3, in order to improve the adhesion between the second silicon carbide 220 and the low temperature silicon oxide film 130, a PSG (Phosphorus Silicate Glass) is formed on the top of the second silicon carbide 220 and the low temperature silicon oxide film 130. E) is deposited to form the first PSG film 140 and the second PSG film 240 (S130). In this case, the first PSG film 140 and the second PSG film 240 may be formed to a thickness of 80 nm to 120 nm, preferably, a thickness of 100 nm. When the first PSG film 140 and the second PSG film 240 are formed, the upper surface of the first PSG film 140 and the second PSG film 240 is polished to improve adhesion.

4 is a cross-sectional view showing a fourth step according to the first embodiment of the present invention, FIG. 5 is a plan view showing a fourth step according to the first embodiment of the present invention, and FIG. 6 is a first embodiment of the present invention. 4 is a plan view illustrating a modified fourth step according to the embodiment. As shown in FIG. 4, etching is performed using exposure etching and wet etching so that grooves 150 of a predetermined depth are formed on one side of the upper surface of the first PSG layer 140 and the low temperature silicon oxide layer 130 (S140). . At this time, the groove 150 is formed in a plurality in a circular shape having a diameter of 100㎛ to 300㎛. As shown in FIG. 5, the plurality of grooves 150 may be etched to be arranged in a rectangular lattice form or as shown in FIG. 6 in a rhombus lattice form. In addition, the depth of the groove 150 is etched so that the remaining thickness of the low temperature silicon oxide film 130 is 200 nm to 500 nm. As such, by adjusting the diameter, pitch, and thickness of the groove 150, the sensitivity and range of the pressure that can be measured can be adjusted. The total area of the groove 150 may not exceed 80% of the total area of the first PSG film 140 and the low temperature silicon oxide film 130. When the total area of the groove 150 exceeds 80% of the total area of the first PSG film 140 and the low temperature silicon oxide film 130, it may be easily damaged by an external impact.

7 is a cross-sectional view showing a fifth step according to the first embodiment of the present invention. As shown in FIG. 7, the first PSG film 140 and the second PSG film 240 face each other, and are then bonded by thermocompression annealing (S150). At this time, the bonding is compressed by using a high pressure at a high temperature of 350 ℃ or more and then slowly cooled to even the internal structure and remove the stress, it is possible to operate at a high temperature of up to 600 ℃ during the operation of the sensor 10.

8 is a cross-sectional view of a capacitive high temperature pressure sensor completed through a sixth step according to the first embodiment of the present invention. Finally, the second silicon wafer 210 is wet-etched with TMAH (Trimethyl Ammonium Hydroxide) to complete the capacitive high temperature pressure sensor 10 (S160).

9 is a graph showing the input and output of the capacitive type high temperature pressure sensor according to the present invention. As shown in FIG. 9, in the completed capacitive high temperature pressure sensor 10, the area between the first silicon carbide and the second silicon carbide 220 of the capacitive pressure sensor 10 is changed by external pressure. As a result, the output varies linearly with the input. In addition, it is excellent in high temperature characteristics and stable, and can be applied to both contact and non-contact modes. Here, the x-axis represents the pressure applied from the outside, the y-axis represents the output value according to the change in the capacitance value due to the change of the interval between the first silicon carbide 120, the lower electrode and the second silicon carbide 220, the upper electrode. Indicates.

(Second embodiment)

10 is a cross-sectional view showing a first step according to the second embodiment of the present invention. First, as shown in FIG. 10, the first silicon wafer 110 and the second silicon wafer 210 are prepared. Such a silicon wafer has a square or rectangular plate shape having a length of 3 mm to 5 mm in width and length, respectively. A first silicon carbide 120 for use as a lower electrode and a second silicon carbide 220 for use as an upper electrode are deposited on the first silicon wafer 110 and the second silicon wafer 210, respectively ( S210). Silicon carbide is an excellent material that hardly deforms at high temperatures, and can be used even at high temperatures when it is deposited to a certain thickness to minimize membrane deformation due to temperature change. Therefore, the first silicon carbide 120 and the second silicon carbide 220 are deposited by a low pressure chemical vapor deposition (LPCVD) to a thickness of 2500nm to 3500nm, preferably 3000nm. If less than 2500 nm, there may occur a problem that the characteristic changes at high temperature, and if it exceeds 3500 nm, the sensor 10 may be insensitive. In this case, when the deposition of the first silicon carbide 120 and the second silicon carbide 220 is completed, the surface of the first silicon carbide 120 and the second silicon carbide 220 may be smoothly deposited for smooth deposition of the first silicon oxide layer (SiO ₂ ) 160 and the second silicon oxide layer 260. Polish

11 is a cross-sectional view showing a second step according to the second embodiment of the present invention. As shown in FIG. 11, the first silicon oxide layer SiO ₂ 160 and the second silicon oxide layer 260, which are insulating layers, are deposited on the first silicon carbide 120 and the second silicon carbide 220, respectively. (S220). In this case, the first silicon oxide film 160 may be deposited to a thickness of 2000 nm to 3000 nm, and preferably, may be deposited to a thickness of 2400 nm. In addition, the second silicon oxide film 260 is preferably deposited at a thickness of 150 nm to 250 nm, but preferably at a thickness of 200 nm. The thinner the thickness of the first silicon oxide film 160 and the second silicon oxide film 260, the more sensitive sensors can be manufactured. However, the thickness of the first silicon oxide film 160 and the second silicon oxide film 260 may be reduced. Since there exists, thickness can be changed suitably according to a use mode. After the deposition of the first silicon oxide film 160 and the second silicon oxide film 260 is completed, the surfaces of the first silicon oxide film 160 and the second silicon oxide film 260 may be CMP (smooth) to smoothly perform the subsequent bonding process. Chemcal-Mechanical Polishing to polish the surface smoothly.

12 is a cross-sectional view showing a third step according to the second embodiment of the present invention. Next, as shown in FIG. 12, etching is performed using exposure etching and wet etching to form a groove 150 having a predetermined depth on one side of the upper surface of the first silicon oxide layer 160 (S230). At this time, the groove 150 is formed in a plurality in a circular shape having a diameter of 100㎛ to 300㎛. The plurality of grooves 150 formed as described above may be etched so as to be arranged in a grid shape of a square, a hexagonal shape, or a rhombus shape. In addition, the depth of the groove 150 is etched so that the remaining thickness of the low temperature silicon oxide film 130 is 200 nm to 500 nm. As such, by adjusting the diameter, pitch, and thickness of the groove 150, the sensitivity and range of the pressure that can be measured can be adjusted. The total area of the grooves 150 may be less than 80% of the total area of the first silicon oxide film 160. If the total area of the groove 150 exceeds 80% of the total area of the first silicon oxide film 160, it may be easily damaged by an external impact.

13 is a cross-sectional view showing a fourth step according to the second embodiment of the present invention. As shown in FIG. 13, the first silicon oxide film 160 and the second silicon oxide film 260 face each other and are then thermally compressed and bonded (S240). At this time, the bonding is compressed by using a high pressure at a temperature of 300 ℃ to 400 ℃ in a vacuum condition of 10 ^-5 mmHg to 10 ^-7 mmHg and then cooled slowly to even out the internal structure and remove the stress to operate the sensor 10 Operation at high temperatures up to 600 ° C is possible.

14 is a cross-sectional view of a capacitive high temperature pressure sensor completed through a fifth step according to the second embodiment of the present invention. As shown in FIG. 14, the second silicon wafer 210 is wet-etched by TMAH (Trimethyl Ammonium Hydroxide) to complete the capacitive high temperature pressure sensor 10 (S250).

Thus completed capacitive high temperature pressure sensor 10, as shown in Figure 9, excellent in high temperature characteristics and stable, can be applied to both contact and contactless mode. Here, the x-axis represents the pressure applied from the outside, the y-axis represents the output value according to the change in the capacitance value due to the change of the interval between the first silicon carbide 120, the lower electrode and the second silicon carbide 220, the upper electrode. Indicates.

<Configuration of the capacitive high temperature pressure sensor>

(First embodiment)

As shown in FIG. 8, the capacitive high temperature pressure sensor 10 according to the first embodiment of the present invention includes a first silicon wafer, a first silicon carbide, a low temperature silicon oxide film 130, and a first PSG film 140. ), A second PSG film 240 and a second silicon carbide 220.

The lowermost part of the capacitive type high temperature pressure sensor 10 according to the first embodiment of the present invention uses a first silicon wafer 110. Such a silicon wafer is commonly used in the art, and a detailed description thereof will be omitted. At this time, the size of the silicon wafer can be changed in consideration of the size of the capacitive type high temperature pressure sensor 10 used, it is preferable to use a silicon wafer having a size of 3mm to 5mm in both the horizontal and vertical length. .

First silicon carbide is formed on the first silicon wafer 110 to be used as a lower electrode. The first silicon carbide 120 is stable even at a high temperature of 500 ° C. At this time, the first silicon carbide may be formed to a thickness of 2500nm to 3500nm. However, it is preferably formed to a thickness of 3000nm. If less than 2500 nm, there may occur a problem that the characteristic changes at a high temperature, and if it exceeds 3500 nm, the sensor 10 may be insensitive.

In order to increase the sensitivity of the capacitive high temperature pressure sensor 10, a low temperature silicon oxide layer 130 having high dielectric constant and high dielectric constant is formed on the first silicon carbide 120. The low temperature silicon oxide film 130 may be formed to a thickness of 2000 nm to 3000 nm, but preferably 2400 nm. If the low-temperature silicon oxide film 130 is less than 2000nm thickness can be a sensitive sensor, but the range is reduced, if the thickness exceeds 3000nm because the sensor becomes wider but the sensor is insensitive to the thickness It can be used by changing suitably according to a use mode. At this time, a circular groove 150 having a diameter of 100 μm to 300 μm is formed in the shape of a fired or rhombus lattice on one side of the low temperature silicon oxide film 130. However, the plurality of grooves 150 are formed within a range not exceeding 80% of the total area of the capacitive high temperature pressure sensor 10 in consideration of durability. In addition, the depth of the groove 150 forms the groove 150 to a depth in which the thickness of the low temperature silicon oxide film 130 forming the bottom of the groove 150 is maintained at a thickness of 200 nm to 500 nm. By changing the pitch, diameter and thickness of the plurality of grooves 150 as described above, the sensitivity and range of the capacitive high temperature pressure sensor 10 can be adjusted.

The first PSG film 140 and the second PSG film 240 for bonding the second silicon carbide 220 described below with the low temperature silicon oxide film 130 are sequentially formed on the low temperature silicon oxide film 130. The first PSG film 140 and the second PSG film 240 may be formed to a thickness of 80 nm to 120 nm, and preferably to a thickness of 100 nm.

A second silicon carbide 220 identical to the first silicon carbide 120 described above is formed on the second PSG film 240 to be used as the upper electrode. At this time, the second silicon carbide is preferably formed to a thickness of 2500nm to 3500nm. However, it is preferably formed to a thickness of 3000nm.

(Second embodiment)

The capacitive type high temperature pressure sensor 10 according to the second embodiment of the present invention includes a first silicon wafer 110, a first silicon carbide 120, a first silicon oxide film 160, and a second silicon oxide film 260. And a second silicon carbide 220.

The first silicon wafer 110 is used as the lowermost part of the capacitive high temperature pressure sensor 10 according to the second embodiment of the present invention. Such a silicon wafer is commonly used in the art, and a detailed description thereof will be omitted. At this time, the size of the silicon wafer can be changed in consideration of the size of the capacitive type high temperature pressure sensor 10 used, it is preferable to use a silicon wafer having a size of 3mm to 5mm in both the horizontal and vertical length.

First silicon carbide is formed on the first silicon wafer 110 to be used as a lower electrode. The first silicon carbide 120 is stable even at a high temperature of 500 ° C. At this time, the first silicon carbide may be formed to a thickness of 2500nm to 3500nm. However, it is preferably formed to a thickness of 3000nm. If less than 2500 nm, there may occur a problem that the characteristic changes at a high temperature, and if it exceeds 3500 nm, the sensor 10 may be insensitive.

In order to increase the sensitivity of the capacitive type high temperature pressure sensor 10, a first silicon oxide layer 160 having good insulation and high dielectric constant is formed on the first silicon carbide 120. The thickness of the first silicon oxide film 160 is preferably formed in a thickness of 2000 nm to 3000 nm, but preferably 2400 nm. The thinner the thickness of the first silicon oxide film 160 and the second silicon oxide film 260, the more sensitive sensors can be manufactured. However, the thickness of the first silicon oxide film 160 and the second silicon oxide film 260 may be reduced. The thickness of the first silicon oxide film 160 can be changed to a suitable thickness according to the use mode. At this time, a circular groove 150 having a diameter of 100 µm to 300 µm has a firing or rhombus lattice. It is formed in the form. However, the plurality of grooves 150 are formed within a range not exceeding 80% of the total area of the capacitive high temperature pressure sensor 10 in consideration of durability. In addition, the depth of the groove 150 forms the groove 150 to a depth at which the thickness of the first silicon oxide film 160 forming the bottom of the groove 150 is maintained at a thickness of 200 nm to 500 nm. By changing the pitch, diameter and thickness of the plurality of grooves 150, the sensitivity and range of the capacitive high temperature pressure sensor 10 can be adjusted.

The second silicon oxide film 260 is formed on the first silicon oxide film 160. The second silicon oxide film 260 is preferably formed to a thickness of 150nm to 250nm, preferably 200nm.

The second silicon carbide 220, which is the same as the first silicon carbide 120 described above, is formed on the second silicon oxide layer 260 and used as the upper electrode. At this time, the second silicon carbide is preferably formed to a thickness of 2500nm to 3500nm. However, it is preferably formed to a thickness of 3000nm.

As described above, those skilled in the art will understand that the present invention can be implemented in other specific forms without changing the technical spirit or essential features. It is therefore to be understood that the above-described embodiments are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present invention.

The following drawings, which are attached in this specification, illustrate the preferred embodiments of the present invention, and together with the detailed description thereof, serve to further understand the technical spirit of the present invention, and therefore, the present invention is limited only to the matters described in the drawings. It should not be interpreted.

1 is a cross-sectional view showing a first step according to a first embodiment of the present invention;

2 is a cross-sectional view showing a second step according to the first embodiment of the present invention;

3 is a cross-sectional view showing a third step according to the first embodiment of the present invention;

4 is a cross-sectional view showing a fourth step according to the first embodiment of the present invention;

5 is a plan view showing a fourth step according to the first embodiment of the present invention;

6 is a plan view showing a fourth modified step according to the first embodiment of the present invention;

7 is a cutaway view showing a fifth step according to the first embodiment of the present invention,

8 is a cross-sectional view of a capacitive high temperature pressure sensor completed through a sixth step according to the first embodiment of the present invention;

9 is a graph showing the input and output of the capacitive type high temperature pressure sensor according to the present invention;

10 is a cross-sectional view showing a first step according to a second embodiment of the present invention;

11 is a cross-sectional view showing a second step according to a second embodiment of the present invention;

12 is a cross-sectional view showing a third step according to a second embodiment of the present invention;

13 is a cross-sectional view showing a fourth step according to a second embodiment of the present invention;

14 is a cross-sectional view of a capacitive high temperature pressure sensor completed through a fifth step according to the second embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

10 sensor 110 first silicon wafer

120: first silicon carbide 130: low temperature silicon oxide film

140: first PSG film 150: groove

160: first silicon oxide film 210: second silicon wafer

220: second silicon carbide 240: second PSG film

260: second silicon oxide film

Claims (25)

A first step (S110) of depositing a first silicon carbide 120 and a second silicon carbide 220 on the first silicon wafer 110 and the second silicon wafer 210, respectively; First and second steps (S120) of depositing a silicon oxide film 130 on the first silicon carbide 120; In order to improve adhesion between the second silicon carbide 220 and the silicon oxide layer 130, PSG is deposited on the silicon oxide layer 130 and the second silicon carbide 220, respectively, to form a first PSG layer 140. ) And forming the second PSG film 240 (S130); A first step (S140) of etching the grooves 150 having a predetermined depth on one side of the upper surfaces of the first PSG film 140 and the silicon oxide film 130; A first step (S150) in which the first PSG film 140 and the second PSG film 240 face each other and then bonded; And 1-6 step (S160) of etching the second silicon wafer (210); manufacturing method of a capacitive pressure sensor comprising a. The method of claim 1, The first step (S110) is a method of manufacturing a capacitive pressure sensor, characterized in that for depositing the first silicon carbide 120 and the second silicon carbide 220 by a low pressure chemical vapor deposition method. The method of claim 1, In the first step (S110), the upper surface of the first silicon carbide 120 is ground to smooth the deposition of the silicon oxide film 130. . The method of claim 1, In the first step (S110), the first silicon carbide 120 and the second silicon carbide 220 are deposited at a thickness of 2500 nm to 3500 nm. The method of claim 1, The first step (S120) is a method of manufacturing a capacitive pressure sensor, characterized in that for depositing the silicon oxide film 130 to a thickness of 2000nm to 3000nm. The method of claim 1, The first step (S130) is a method of manufacturing a capacitive pressure sensor, characterized in that for depositing the first PSG film 140 and the second PSG film 240 to a thickness of 80nm to 120nm. The method of claim 1, In the first to third steps S130, the first PSG film 140 and the second PSG film 240 may be improved to improve adhesion between the first PSG film 140 and the second PSG film 240. The manufacturing method of the capacitive pressure sensor, characterized in that for polishing the upper surface. The method of claim 1, Wherein the step 1-4 (S140) is a method of manufacturing a capacitive pressure sensor, characterized in that for forming a plurality of grooves (150). The method of claim 8, The groove 150 is a method of manufacturing a capacitive pressure sensor, characterized in that arranged in a regular grid. The method of claim 1, The first step (S140) is a method of manufacturing a capacitive pressure sensor, characterized in that to form a groove (150) by using at least one of the exposure etching and wet etching. The method of claim 1, The 1-5 step (S150) is a manufacturing method of the capacitive pressure sensor, characterized in that the bonding by thermal compression. The method of claim 1, Method 1-6 (S160) is a method of manufacturing a capacitive pressure sensor, characterized in that the TMAH wet etching the second silicon wafer (210). A step 2-1 (S210) of depositing a first silicon carbide 120 and a second silicon carbide 220 on the first silicon wafer 110 and the second silicon wafer 210, respectively; A second step (S220) of depositing a first silicon oxide film 160 and a second silicon oxide film 260 on the first silicon carbide 120 and the second silicon carbide 220, respectively; An etching step 2-3 of forming a groove 150 having a predetermined depth on an upper side of the first silicon oxide layer 160 (S230); A second step (S240) in which the first silicon oxide film 160 and the second silicon oxide film 260 face each other and then bonded; And And a second to fifth steps (S250) of etching the second silicon wafer (210). The method of claim 13, The 2-1 step (S210) is a method of manufacturing a capacitive pressure sensor, characterized in that for depositing the first silicon carbide 120 and the second silicon carbide 220 by a low pressure chemical vapor deposition method. The method of claim 13, The second step S210 may include depositing the first silicon oxide layer 160 and the second silicon oxide layer 260 on the upper surfaces of the first silicon carbide 120 and the second silicon carbide 220. Method for producing a capacitive pressure sensor, characterized in that for polishing to smooth. The method of claim 13, The first silicon carbide 120 and the second silicon carbide 220 in the step 2-1 (S210) is deposited to a thickness of 2500nm to 3500nm method of manufacturing a capacitive pressure sensor. The method of claim 13, The step 2-2 (S220) of the capacitive pressure sensor, characterized in that for chemical-Mechanical Polishing the upper surface for smooth adhesion of the first silicon oxide film 160 and the second silicon oxide film 260. Manufacturing method. The method of claim 13, In the second step (S220), the first silicon dioxide is deposited to a thickness of 2000nm to 3000nm, and the second silicon oxide film 260 is deposited to a thickness of 150nm to 250nm. Way. The method of claim 13, The second step (S230) is a method of manufacturing a capacitive pressure sensor, characterized in that to form a plurality of grooves (150). The method of claim 19, The groove 150 is a method of manufacturing a capacitive pressure sensor, characterized in that arranged in a regular grid. The method of claim 13, The second step (S230) is a method of manufacturing a capacitive pressure sensor, characterized in that to form a groove (150) using at least one of exposure etching and wet etching. The method of claim 13, Step 2-4 (S240) is a method of manufacturing a capacitive pressure sensor, characterized in that the bonding by thermal compression. 23. The method of claim 22, The thermocompression method of manufacturing a capacitive pressure sensor, characterized in that the thermocompression bonding at a temperature of 300 ℃ to 400 ℃, in a vacuum condition of 10 ^-5 mmHg to 10 ^-7 mmHg. The method of claim 13, Step 2-5 (S250) is a method of manufacturing a capacitive pressure sensor, characterized in that the TMAH wet etching the second silicon wafer (210). A capacitive pressure sensor according to any one of claims 1 to 24.

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