Manufacturing process of SDB type silicon MEMS high-temperature pressure sensor

Abstract

The invention discloses a manufacturing process of an SDB type silicon MEMS high-temperature pressure sensor, and relates to the technical field of pressure detection devices of micro electro mechanical systems, and the manufacturing process comprises the following steps: S1, preparing an SOI material based on a silicon substrate; s2, photoetching a resistor region, and carrying out ion implantation; s3, photoetching a corrosion protection area; s4, carrying out wet etching; s5, manufacturing a lead hole and a metal lead; step S6, metallization and passivation are carried out; and S7, photoetching a back corrosion region. According to the manufacturing process of the SDB type silicon MEMS high-temperature pressure sensor, the surface of the pressure sensitive resistor is not damaged, and the uniformity and consistency are good.

Description

Technical Field

[0001] The invention relates to the technical field of pressure detection devices of micro-electromechanical systems, and in particular to a manufacturing process of a SDB type silicon MEMS high-temperature pressure sensor. Background Art

[0002] MEMS, or micro-electromechanical system, is an emerging interdisciplinary high-tech research field. Piezoresistive pressure sensors manufactured based on MEMS technology have been widely used in the modern market due to their excellent accuracy and reliability as well as relatively low manufacturing costs. Silicon MEMS high-temperature pressure sensor is a common pressure sensor. Because it can work normally in high temperature environments, it is widely used in pressure measurement in aviation, aerospace engine testing and weapons industry. Almost all ignition process tests and research cannot be separated from the participation of silicon MEMS high-temperature pressure sensors.

[0003] At present, the manufacturing methods of silicon MEMS high temperature pressure sensors mainly include bulk silicon processing technology and surface processing technology. In essence, both technologies rely on some kind of etching or adding materials, which have certain limitations. With the rapid development of micromachining technology, SDB technology has gradually become a key technology for high-performance sensors with its excellent temperature performance. SDB technology refers to the process of combining two materials closely together through chemical and physical effects to form a reliable physical connection. This technology is an important method for preparing complex and reliable silicon structures.

[0004] In the usual production process of silicon MEMS high-temperature pressure sensors, the four resistors that make up the Wheatstone bridge of the pressure sensor are made of four mechanical dimensions and resistors with exactly the same aspect ratio by photolithography. Then the single crystal silicon of the device layer outside the resistor area is etched away by dry etching. In this way, the remaining four varistors have a highly sensitive piezoresistive effect, and their vertical and horizontal arrangements have opposite piezoresistance changes. At the same time, the neat and uniform dry etching also makes the zero-point output of the Wheatstone bridge composed of four resistors, that is, the offset voltage, relatively small. Generally, under a 5V power supply voltage, the offset voltage can be within 10 millivolts. It is convenient for subsequent circuit signal processing. However, this process method also has certain problems. First, the dry etching equipment is relatively expensive, and the working efficiency is not high during deep etching; second, the plasma used in the dry etching process bombards the surface of the silicon device, which will cause certain lattice damage and stress effects on the surface of the silicon device, which is a significant adverse effect in the production of high-performance, high-precision, and high-stability pressure sensors.

[0005] In order to solve the above problems, the current common practice is to use wet etching process instead of dry etching. However, the traditional wet etching process has an obvious shortcoming, that is, the uniformity of wet etching is not high. The main reason is that the end point of wet etching is not easy to control. The concentration of the corrosion liquid changes with the corrosion consumption, the corrosion end point is not easy to detect, and the length of the corrosion end time is not easy to determine, which will cause wet corrosion to the resistance area. The corrosion progress is uneven. Ultimately, the resistance uniformity of the four bridge arms of the Wheatstone bridge is not consistent, which leads to the final voltage output value of the Wheatstone bridge, that is, the offset voltage, being too large.

[0006] It can be seen that the development of a SDB-type silicon MEMS high-temperature pressure sensor manufacturing process with no damage to the surface of the pressure sensitive resistor and good uniformity and consistency meets the market demand, has broad market value and application prospects, and is of great significance to promoting the development of the MEMS field. Summary of the invention

[0007] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a SDB type silicon MEMS high temperature pressure sensor manufacturing process with no damage to the surface of the pressure sensitive resistor and good uniformity and consistency.

[0008] To achieve the above object, the technical solution adopted by the present invention is: a SDB type silicon MEMS high temperature pressure sensor manufacturing process, comprising the following steps: Step S1, preparation of SOI material based on silicon substrate: select two double-polished silicon wafers, use a high-temperature oxidation method to oxidize the front side of the silicon wafer to generate a silicon dioxide insulating layer, then bond the silicon dioxide insulating layers of the two silicon wafers together in a ethylene glycol solution of ditrihydroxymethylaminopropane, take them out and heat them on a flat and smooth iron plate electric furnace, then bake them in an oven, use nitrogen protection to complete pre-bonding, and then perform annealing under nitrogen protection; finally, thin the top silicon wafer to obtain an SOI material based on a silicon substrate; Step S2, photolithography resistance area, ion implantation: using the silicon substrate-based SOI material manufactured in step S1 as a substrate, defining a resistance area on the front side of the substrate by photolithography, and manufacturing the resistance area by ion implantation, and then activating the implanted ions by high temperature thermal annealing; Step S3, photolithography corrosion protection area: defining the corrosion protection area on the front side of the substrate by photolithography; Step S4, wet etching: manufacturing the varistor by wet etching; Step S5, making lead holes and metal leads: making lead holes and metal leads on the front side of the substrate; Step S6, metallization and passivation: sputtering a metal layer for connecting the piezoresistive resistor on the varistor manufactured in step S4 to form a Wheatstone bridge, and depositing a passivation layer on the upper surface of the device by chemical vapor deposition to protect the device; Step S7, photolithography of the backside corrosion area: performing photolithography on the backside corrosion area.

[0009] Preferably, the temperature of the high temperature oxidation in step S1 is 930-1230° C., the oxygen flow rate is controlled at 0.7-1.3 cm / s, and the thickness of the silicon dioxide insulating layer is ≤300 nm.

[0010] Preferably, the mass percentage concentration of the ethylene glycol solution of ditrihydroxymethylaminopropane in step S1 is 3-8wt%.

[0011] Preferably, the heating temperature in step S1 is 185-195° C. and the heating time is 2-4 hours.

[0012] Preferably, the baking temperature in step S1 is 290-330° C. and the baking time is 3-5 hours.

[0013] Preferably, the annealing treatment in step S1 is performed at a temperature of 1090-1120° C. for 1-2 h.

[0014] Preferably, the thinning process in step S1 is performed by mechanical grinding and polishing.

[0015] Preferably, the ion implanted in step S1 is boron ion or ion of other group III elements, and the ion implantation dose is 1×10 19 ~1×10 21 atoms / cm2.

[0016] Preferably, the high temperature thermal annealing in step S2 is performed at a temperature of 1120-1180° C., for a time of 14-25 min, under nitrogen atmosphere protection.

[0017] Preferably, the corrosion protection zone in step S2 is located at the outer edge of the resistance zone, and the resistance zone is included in the corrosion protection zone.

[0018] Preferably, the wet etching in step S4 is isotropic etching, and the etching solution used comprises the following components in weight percentage: acetic acid 20-25wt%, hydrofluoric acid 8-10wt%, tea polyphenols 1-3wt%, trimethylolmethylglycine 1-3wt%, H 2 O 2 8-10wt%, the balance is deionized water.

[0019] Due to the application of the above technical solution, the present invention has the following beneficial effects: (1) The SDB type silicon MEMS high temperature pressure sensor manufacturing process disclosed in the present invention has low process difficulty, high reliability, is easy to obtain a high yield rate, has low dependence on equipment, is suitable for continuous large-scale production, and has high promotion and application value.

[0020] (2) The SDB type silicon MEMS high temperature pressure sensor manufacturing process disclosed in the present invention adopts SOI material based on silicon substrate as the substrate, so that the final pressure sensor has high measurement sensitivity and accuracy, and has better temperature performance and ultra-high stability; outside the photolithography varistor area, the secondary photolithography etching protection area is carried out, and then wet etching is performed, so that the lateral corrosion of the wet etching will not affect the resistance value of the bridge arm resistor of the Wheatstone bridge, thereby reducing the offset voltage; the four pressure sensitive resistors of the Wheatstone bridge can be manufactured without surface damage, and the uniformity and consistency of the four pressure sensitive resistors of the Wheatstone bridge can be guaranteed, so that the final offset voltage reaches the same level as or even higher than that of dry etching.

[0021] (3) The SDB type silicon MEMS high temperature pressure sensor manufacturing process disclosed in the present invention, the wet etching is isotropic etching, and the etching solution used includes the following components in weight percentage: acetic acid 20-25wt%, hydrofluoric acid 8-10wt%, tea polyphenols 1-3wt%, trimethylol methylglycine 1-3wt%, H 2 O 2 8-10wt%, the balance is deionized water. By rationally selecting the composition formula of the etching solution, the components can better interact with each other, thereby effectively improving the etching effect and efficiency. By rationally selecting the process parameters, the process steps can be simplified, the process reliability and the device yield can be improved, the device can be guaranteed to work normally in a high temperature environment, and the application range of the sensor can be broadened. In the preparation process of SOI materials based on silicon substrates, the bonding in ethylene glycol solution of ditrihydroxymethylaminopropane can effectively improve the bonding strength and stability. DETAILED DESCRIPTION

[0022] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art may think of other obvious variations.

[0023] Embodiment 1, a SDB type silicon MEMS high temperature pressure sensor manufacturing process, comprising the following steps: Step S1, preparation of SOI material based on silicon substrate: select two double-polished silicon wafers, use a high-temperature oxidation method to oxidize the front side of the silicon wafer to generate a silicon dioxide insulating layer, then bond the silicon dioxide insulating layers of the two silicon wafers together in a ethylene glycol solution of ditrihydroxymethylaminopropane, take them out and heat them on a flat and smooth iron plate electric furnace, then bake them in an oven, use nitrogen protection to complete pre-bonding, and then perform annealing under nitrogen protection; finally, thin the top silicon wafer to obtain an SOI material based on a silicon substrate; Step S2, photolithography resistance area, ion implantation: using the silicon substrate-based SOI material manufactured in step S1 as a substrate, defining a resistance area on the front side of the substrate by photolithography, and manufacturing the resistance area by ion implantation, and then activating the implanted ions by high temperature thermal annealing; Step S3, photolithography corrosion protection area: defining the corrosion protection area on the front side of the substrate by photolithography; Step S4, wet etching: manufacturing the varistor by wet etching; Step S5, making lead holes and metal leads: making lead holes and metal leads on the front side of the substrate; Step S6, metallization and passivation: sputtering a metal layer for connecting the piezoresistive resistor on the varistor manufactured in step S4 to form a Wheatstone bridge, and depositing a passivation layer on the upper surface of the device by chemical vapor deposition to protect the device; Step S7, photolithography of the backside corrosion area: performing photolithography on the backside corrosion area.

[0024] The temperature of high temperature oxidation in step S1 is 930°C, the oxygen flow rate is controlled at 0.7 cm / s, and the thickness of the silicon dioxide insulating layer is ≤300 nm; the mass percentage concentration of the ethylene glycol solution of ditrihydroxymethylaminopropane in step S1 is 3wt%; the heating temperature in step S1 is 185°C and the time is 2h; the baking temperature in step S1 is 290°C and the time is 3h; the annealing temperature in step S1 is 1090°C and the time is 1h; the thinning treatment in step S1 is performed by mechanical grinding and polishing; the ion implanted substance in step S1 is boron ions or ions of other group III elements, and the ion implantation dose is 1×10 19 atoms / cm2.

[0025] The high temperature thermal annealing in step S2 is performed at a temperature of 1120° C. for 14 minutes under nitrogen atmosphere protection; the corrosion protection zone in step S2 is located at the outer edge of the resistance zone, and the resistance zone is included in the corrosion protection zone.

[0026] The wet etching in step S4 is isotropic etching, and the etching solution used includes the following components in weight percentage: acetic acid 20wt%, hydrofluoric acid 8wt%, tea polyphenols 1wt%, trimethylolmethylglycine 1wt%, H 2 O 2 8wt%, the balance is deionized water.

[0027] Embodiment 2, a SDB type silicon MEMS high temperature pressure sensor manufacturing process, comprising the following steps: Step S1, preparation of SOI material based on silicon substrate: select two double-polished silicon wafers, use a high-temperature oxidation method to oxidize the front side of the silicon wafer to generate a silicon dioxide insulating layer, then bond the silicon dioxide insulating layers of the two silicon wafers together in a ethylene glycol solution of ditrihydroxymethylaminopropane, take them out and heat them on a flat and smooth iron plate electric furnace, then bake them in an oven, use nitrogen protection to complete pre-bonding, and then perform annealing under nitrogen protection; finally, thin the top silicon wafer to obtain an SOI material based on a silicon substrate; Step S2, photolithography resistance area, ion implantation: using the silicon substrate-based SOI material manufactured in step S1 as a substrate, defining a resistance area on the front side of the substrate by photolithography, and manufacturing the resistance area by ion implantation, and then activating the implanted ions by high temperature thermal annealing; Step S3, photolithography corrosion protection area: defining the corrosion protection area on the front side of the substrate by photolithography; Step S4, wet etching: manufacturing the varistor by wet etching; Step S5, making lead holes and metal leads: making lead holes and metal leads on the front side of the substrate; Step S6, metallization and passivation: sputtering a metal layer for connecting the piezoresistive resistor on the varistor manufactured in step S4 to form a Wheatstone bridge, and depositing a passivation layer on the upper surface of the device by chemical vapor deposition to protect the device; Step S7, photolithography of the backside corrosion area: performing photolithography on the backside corrosion area.

[0028] The temperature of high temperature oxidation in step S1 is 1030°C, the oxygen flow rate is controlled at 0.8 cm / s, and the thickness of the silicon dioxide insulating layer is ≤300 nm; the mass percentage concentration of the ethylene glycol solution of ditrihydroxymethylaminopropane in step S1 is 4wt%; the heating temperature in step S1 is 187°C and the time is 2.5 h; the baking temperature in step S1 is 300°C and the time is 3.5 h; the annealing temperature in step S1 is 1100°C and the time is 1.2 h; the thinning treatment in step S1 is performed by mechanical grinding and polishing; the ion implanted substance in step S1 is boron ions or ions of other group III elements, and the ion implantation dose is 6×1019 atoms / cm2.

[0029] The high temperature thermal annealing in step S2 is performed at a temperature of 1140° C. for 17 minutes under nitrogen atmosphere protection; the corrosion protection zone in step S2 is located at the outer edge of the resistance zone, and the resistance zone is included in the corrosion protection zone.

[0030] The wet etching in step S4 is isotropic etching, and the etching solution used includes the following components in weight percentage: acetic acid 22wt%, hydrofluoric acid 8.5wt%, tea polyphenols 1.5wt%, trimethylolmethylglycine 1.5wt%, H 2 O 2 8.5wt%, the balance is deionized water.

[0031] Embodiment 3, a SDB type silicon MEMS high temperature pressure sensor manufacturing process, comprising the following steps: Step S1, preparation of SOI material based on silicon substrate: select two double-polished silicon wafers, use a high-temperature oxidation method to oxidize the front side of the silicon wafer to generate a silicon dioxide insulating layer, then bond the silicon dioxide insulating layers of the two silicon wafers together in a ethylene glycol solution of ditrihydroxymethylaminopropane, take them out and heat them on a flat and smooth iron plate electric furnace, then bake them in an oven, use nitrogen protection to complete pre-bonding, and then perform annealing under nitrogen protection; finally, thin the top silicon wafer to obtain an SOI material based on a silicon substrate; Step S2, photolithography resistance area, ion implantation: using the silicon substrate-based SOI material manufactured in step S1 as a substrate, defining a resistance area on the front side of the substrate by photolithography, and manufacturing the resistance area by ion implantation, and then activating the implanted ions by high temperature thermal annealing; Step S3, photolithography corrosion protection area: defining the corrosion protection area on the front side of the substrate by photolithography; Step S4, wet etching: manufacturing the varistor by wet etching; Step S5, making lead holes and metal leads: making lead holes and metal leads on the front side of the substrate; Step S6, metallization and passivation: sputtering a metal layer for connecting the piezoresistive resistor on the varistor manufactured in step S4 to form a Wheatstone bridge, and depositing a passivation layer on the upper surface of the device by chemical vapor deposition to protect the device; Step S7, photolithography of the backside corrosion area: performing photolithography on the backside corrosion area.

[0032] The temperature of high temperature oxidation in step S1 is 1100°C, the oxygen flow rate is controlled at 1cm / s, and the thickness of the silicon dioxide insulating layer is ≤300nm; the mass percentage concentration of the ethylene glycol solution of ditrihydroxymethylaminopropane in step S1 is 6wt%; the heating temperature in step S1 is 190°C and the time is 3h; the baking temperature in step S1 is 310°C and the time is 4h; the annealing temperature in step S1 is 1105°C and the time is 1.5h; the thinning treatment in step S1 is performed by mechanical grinding and polishing; the ion implanted substance in step S1 is boron ions or ions of other group III elements, and the ion implantation dose is 1×10 20 atoms / cm2.

[0033] The temperature of the high temperature thermal annealing in step S2 is 1150° C., the time is 20 min, and the nitrogen atmosphere is used for protection; the corrosion protection zone in step S2 is located at the outer edge of the resistance zone, and the resistance zone is included in the corrosion protection zone; the wet etching in step S4 is isotropic etching, and the etching solution used includes the following components in weight percentage: acetic acid 23wt%, hydrofluoric acid 9wt%, tea polyphenols 2wt%, trimethylol methylglycine 2wt%, H 2 O 2 9wt%, the balance being deionized water.

[0034] Embodiment 4, a SDB type silicon MEMS high temperature pressure sensor manufacturing process, comprising the following steps: Step S1, preparation of SOI material based on silicon substrate: select two double-polished silicon wafers, use a high-temperature oxidation method to oxidize the front side of the silicon wafer to generate a silicon dioxide insulating layer, then bond the silicon dioxide insulating layers of the two silicon wafers together in a ethylene glycol solution of ditrihydroxymethylaminopropane, take them out and heat them on a flat and smooth iron plate electric furnace, then bake them in an oven, use nitrogen protection to complete pre-bonding, and then perform annealing under nitrogen protection; finally, thin the top silicon wafer to obtain an SOI material based on a silicon substrate; Step S2, photolithography resistance area, ion implantation: using the silicon substrate-based SOI material manufactured in step S1 as a substrate, defining a resistance area on the front side of the substrate by photolithography, and manufacturing the resistance area by ion implantation, and then activating the implanted ions by high temperature thermal annealing; Step S3, photolithography corrosion protection area: defining the corrosion protection area on the front side of the substrate by photolithography; Step S4, wet etching: manufacturing the varistor by wet etching; Step S5, making lead holes and metal leads: making lead holes and metal leads on the front side of the substrate; Step S6, metallization and passivation: sputtering a metal layer for connecting the piezoresistive resistor on the varistor manufactured in step S4 to form a Wheatstone bridge, and depositing a passivation layer on the upper surface of the device by chemical vapor deposition to protect the device; Step S7, photolithography of the backside corrosion area: performing photolithography on the backside corrosion area.

[0035] The temperature of the high temperature oxidation in step S1 is 1200°C, the oxygen flow rate is controlled at 1.2 cm / s, and the thickness of the silicon dioxide insulating layer is ≤300 nm; the mass percentage concentration of the ethylene glycol solution of ditrihydroxymethylaminopropane in step S1 is 7wt%; the heating temperature in step S1 is 193°C and the time is 3.5 h; the baking temperature in step S1 is 320°C and the time is 4.5 h; the annealing temperature in step S1 is 1110°C and the time is 1.8 h; the thinning treatment in step S1 is performed by mechanical grinding and polishing; the ion implanted substance in step S1 is boron ions or ions of other group III elements, and the ion implantation dose is 5×10 20 atoms / cm2.

[0036] The high temperature thermal annealing in step S2 is performed at a temperature of 1170° C. for 23 minutes under nitrogen atmosphere protection; the corrosion protection zone in step S2 is located at the outer edge of the resistance zone, and the resistance zone is included in the corrosion protection zone.

[0037] The wet etching in step S4 is isotropic etching, and the etching solution used includes the following components in weight percentage: acetic acid 24wt%, hydrofluoric acid 9.5wt%, tea polyphenols 2.5wt%, trimethylolmethylglycine 2.5wt%, H 2 O 2 9.5wt%, the balance being deionized water.

[0038] Embodiment 5, a SDB type silicon MEMS high temperature pressure sensor manufacturing process, comprising the following steps: Step S1, preparation of SOI material based on silicon substrate: select two double-polished silicon wafers, use a high-temperature oxidation method to oxidize the front side of the silicon wafer to generate a silicon dioxide insulating layer, then bond the silicon dioxide insulating layers of the two silicon wafers together in a ethylene glycol solution of ditrihydroxymethylaminopropane, take them out and heat them on a flat and smooth iron plate electric furnace, then bake them in an oven, use nitrogen protection to complete pre-bonding, and then perform annealing under nitrogen protection; finally, thin the top silicon wafer to obtain an SOI material based on a silicon substrate; Step S2, photolithography resistance area, ion implantation: using the silicon substrate-based SOI material manufactured in step S1 as a substrate, defining a resistance area on the front side of the substrate by photolithography, and manufacturing the resistance area by ion implantation, and then activating the implanted ions by high temperature thermal annealing; Step S3, photolithography corrosion protection area: defining the corrosion protection area on the front side of the substrate by photolithography; Step S4, wet etching: manufacturing the varistor by wet etching; Step S5, making lead holes and metal leads: making lead holes and metal leads on the front side of the substrate; Step S6, metallization and passivation: sputtering a metal layer for connecting the piezoresistive resistor on the varistor manufactured in step S4 to form a Wheatstone bridge, and depositing a passivation layer on the upper surface of the device by chemical vapor deposition to protect the device; Step S7, photolithography of the backside corrosion area: performing photolithography on the backside corrosion area.

[0039] The temperature of high temperature oxidation in step S1 is 1230°C, the oxygen flow rate is controlled at 1.3 cm / s, and the thickness of the silicon dioxide insulating layer is ≤300 nm; the mass percentage concentration of the ethylene glycol solution of ditrihydroxymethylaminopropane in step S1 is 8wt%; the heating temperature in step S1 is 195°C and the time is 4h; the baking temperature in step S1 is 330°C and the time is 5h; the annealing temperature in step S1 is 1120°C and the time is 2h; the thinning treatment in step S1 is performed by mechanical grinding and polishing; the ion implanted substance in step S1 is boron ions or ions of other group III elements, and the ion implantation dose is 1×10 21 atoms / cm2.

[0040] The high temperature thermal annealing in step S2 is performed at a temperature of 1180° C. for 25 minutes under nitrogen atmosphere protection; the corrosion protection zone in step S2 is located at the outer edge of the resistance zone, and the resistance zone is included in the corrosion protection zone.

[0041] The wet etching in step S4 is isotropic etching, and the etching solution used includes the following components in weight percentage: acetic acid 25wt%, hydrofluoric acid 10wt%, tea polyphenols 3wt%, trimethylolmethylglycine 3wt%, H 2 O 2 10wt%, the balance is deionized water.

[0042] Comparative Example A SDB type silicon MEMS high temperature pressure sensor manufacturing process is basically the same as that of Example 1, except that tea polyphenols and trishydroxymethyl methylglycine are not added to the etching solution, and there is no step of photolithography etching protection area.

[0043] In order to further illustrate the beneficial technical effects of the SDB-type silicon MEMS high-temperature pressure sensor manufacturing process involved in each embodiment of the present invention, relevant performance tests were carried out on the sensors made by the SDB-type silicon MEMS high-temperature pressure sensor manufacturing process involved in Examples 1-5 and the comparative example. The test results show that the pressure sensitive resistors of the sensors made in Examples 1-5 have no damage on the surface, and have good uniformity and consistency; while the pressure sensitive resistors of the sensors of the comparative example products have obvious damage on the surface, and have poor uniformity and consistency.

[0044] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the contents of the present invention and implement them accordingly. They cannot be used to limit the protection scope of the present invention. All equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A SDB type silicon MEMS high temperature pressure sensor manufacturing process, characterized in that: The steps include: Step S1, preparation of SOI material based on silicon substrate: select two double-polished silicon wafers, use a high-temperature oxidation method to oxidize the front side of the silicon wafer to generate a silicon dioxide insulating layer, then bond the silicon dioxide insulating layers of the two silicon wafers together in a ethylene glycol solution of ditrihydroxymethylaminopropane, take them out and heat them on a flat and smooth iron plate electric furnace, then bake them in an oven, use nitrogen protection to complete pre-bonding, and then perform annealing under nitrogen protection; finally, thin the top silicon wafer to obtain an SOI material based on a silicon substrate; Step S2, photolithography resistance area, ion implantation: using the silicon substrate-based SOI material manufactured in step S1 as a substrate, defining a resistance area on the front side of the substrate by photolithography, and manufacturing the resistance area by ion implantation, and then activating the implanted ions by high temperature thermal annealing; Step S3, photolithography corrosion protection area: defining the corrosion protection area on the front side of the substrate by photolithography; Step S4, wet etching: manufacturing the varistor by wet etching; Step S5, making lead holes and metal leads: making lead holes and metal leads on the front side of the substrate; Step S6, metallization and passivation: sputtering a metal layer for connecting the piezoresistive resistor on the varistor manufactured in step S4 to form a Wheatstone bridge, and depositing a passivation layer on the upper surface of the device by chemical vapor deposition to protect the device; Step S7, photolithography of the backside corrosion area: performing photolithography on the backside corrosion area.

2. The SDB type silicon MEMS high temperature pressure sensor manufacturing process according to claim 1 is characterized in that: The temperature of the high temperature oxidation in step S1 is 930-1230° C., the oxygen flow rate is controlled at 0.7-1.3 cm / s, and the thickness of the silicon dioxide insulating layer is ≤300 nm.

3. The SDB type silicon MEMS high temperature pressure sensor manufacturing process according to claim 1 is characterized in that: The mass percentage concentration of the ethylene glycol solution of ditrihydroxymethylaminopropane in step S1 is 3-8wt%.

4. The SDB type silicon MEMS high temperature pressure sensor manufacturing process according to claim 1 is characterized in that: The heating temperature in step S1 is 185-195° C., and the time is 2-4 hours; the baking temperature in step S1 is 290-330° C., and the time is 3-5 hours.

5. The SDB type silicon MEMS high temperature pressure sensor manufacturing process according to claim 1 is characterized in that: The temperature of the annealing treatment in step S1 is 1090-1120° C., and the time is 1-2 hours; the thinning treatment in step S1 is performed by mechanical grinding and polishing.

6. The SDB type silicon MEMS high temperature pressure sensor manufacturing process according to claim 1, characterized in that: The ion implanted in step S1 is boron ion or other ions of group III elements, and the ion implantation dose is 1×10 19 ~1×10 21 atoms / cm2.

7. The SDB type silicon MEMS high temperature pressure sensor manufacturing process according to claim 1, characterized in that: The high temperature thermal annealing in step S2 is performed at a temperature of 1120-1180° C. for 14-25 min under a nitrogen atmosphere.

8. The SDB type silicon MEMS high temperature pressure sensor manufacturing process according to claim 1, characterized in that: In step S2, the corrosion protection zone is located at the outer edge of the resistance zone, and the resistance zone is included in the corrosion protection zone.

9. The SDB type silicon MEMS high temperature pressure sensor manufacturing process according to claim 1, characterized in that: The wet etching in step S4 is isotropic etching, and the etching solution used includes the following components in weight percentage: acetic acid 20-25wt%, hydrofluoric acid 8-10wt%, tea polyphenols 1-3wt%, trimethylolmethylglycine 1-3wt%, H2O2 8-10wt%, and the balance is deionized water.