CN1094653C

CN1094653C - Technology for manufacturing chip of high-temp pressure sensor

Info

Publication number: CN1094653C
Application number: CN 99124237
Authority: CN
Inventors: 张轩雄; 陆德仁; 王文襄; 杨根庆
Original assignee: Shanghai Institute of Metallurgy of CAS
Current assignee: Shanghai Institute of Optics and Fine Mechanics of CAS
Priority date: 1999-12-10
Filing date: 1999-12-10
Publication date: 2002-11-20
Anticipated expiration: 2019-12-10
Also published as: CN1255734A

Abstract

The present invention relates to a method for manufacturing chips of a high temperature pressure sensor, which is characterized in that a silicon chip with a single crystal carborundum epitaxial layer and a silicon chip with an oxidized external layer are washed by concentrated sulfuric acid and flushed by deionized water; afterwards, the carborundum surface of the silicon chip is bonded with the silicon oxide surface of the other silicon chip; then, the silicon chips are put in a potassium hydroxide solution for corrosion; a substrate silicon layer of the carborundum epitaxial layer is removed. Thus, the technology for manufacturing chips of a high temperature pressure sensor is simplified, and the sufficient exertion of the high temperature semiconductor characteristics of single crystal carborundum of the manufactured chips can be ensured.

Description

The manufacture method of chip of high-temp pressure sensor

Technical field

The present invention relates to high-temp pressure sensor, the particularly making of carborundum (SiC) chip of high-temp pressure sensor on the insulator.

Background technology

Pressure sensor is widely used in industrial process control, is indispensable parts in the industrial production.A lot of such measurement components need use under hot environment, are particularly measuring more than 450 ℃, are different from the miscellaneous part of transducer as the sensor chip of senser, and it inevitably must stand high temperature.Because the high temperature semiconductors characteristic of carborundum can utilize its piezoresistive effect to carry out high temperature pressure measurement.Monocrystalline silicon carbide only can extension come out on monocrystalline substrate at present, on insulator, can only grow polycrystal carborundum, and the piezoresistive effect of polycrystal carborundum is not as monocrystalline, the carborundum that at high temperature uses particularly, the monocrystalline performance is better than polycrystalline, and the formation of carborundum has utilized insulator to make electricity isolated layer on the insulator, can get rid of the interference of silicon substrate under the high temperature measurement, simultaneously can utilize silicon again as flexible member, so silica (SiO ₂) be best choice as insulator.

14 to 18 June in 1998, the 245-249 page or leaf in the 8th the high temperature electronics proceedings that New Mexico Ah Bai chief's gram (Albuquerque) is held was once reported, on the silicon on the insulator (Silieon On Insulater) substrate, utilize the upper strata silicon epitaxy to go out C type monocrystalline silicon carbide (SiC), utilize the carborundum of silicon-on-insulator to carry out the making of high-temp pressure sensor.

1 to 4 September in 1998, the 87-88 page or leaf in the European proceedings of carborundum that Vermont, France Gloriane Perrier (Montpellier) is held and associated materials was reported the upper strata silicon of the silicon on insulator (SOI) and buried regions silica (SiO again ₂) between with the nitrogenize silicon/oxidative silicon (SiO of system ₃N ₄/ SiO ₂) do the barrier layer that upper strata silicon spreads, to obtain stable SiC/SOI material system.The carborundum high-temp pressure sensor of making in aforementioned two pieces of lists of references all is to be that the single-crystal silicon carbide that goes out by extension on silicon single crystal on SOI (the Silicon on insulator) substrate is directly made at the silicon on the insulator, therefore its substrate has kept the substrate monocrystal silicon layer of using as the epitaxial silicon carbide monocrystalline, and silicon will lose characteristic of semiconductor substantially in the time of about 350 ℃-400 ℃, therefore in this temperature (350 ℃-400 ℃ or more than) when measuring down, this silicon layer will have a negative impact, and the high temperature semiconductors characteristic of carborundum can not be not fully exerted.

Summary of the invention

The technical problem to be solved in the present invention is in order to overcome the defective of said method, provide a kind of on insulator the manufacture method of carborundum chip of high-temp pressure sensor, manage to have removed monocrystalline silicon layer as the silicon carbide epitaxy single crystalline substrate, thereby the negative effect of silicon layer substrate can eliminate high temperature measurement the time.

Technical solution of the present invention realizes that by the following method it may further comprise the steps: (1) carries out high-temperature oxydation to certain thickness silicon chip; (2), silicon chip and another silicon chip that has the monocrystalline silicon carbide epitaxial loayer with first step oxidation cleans with the concentrated sulfuric acid, use deionized water rinsing again, wherein the silicon carbide surface of silicon chip and the oxidation silicon face of another silicon chip fit tightly together then, and sending into 1000 ℃ of soaks carried out bonding in 3 hours; (3), put into potassium hydroxide solution and corrode, remove the substrate silicon layer of silicon carbide epitaxy, stay silicon carbide epitaxial layers; (4), make mask, make resistance full-bridge figure by lithography, go out silicon embossment resistance full-bridge with dry etching with metallic aluminium; (5), at surface deposition one deck silicon nitride (Si of resistance full-bridge ₃N ₄); (6), making lead-in wire with aluminium traditionally at last anti-carves and alloying.

It is 1150 ℃ of following oxidations that said silicon chip carries out the high-temperature oxydation program, 15 minutes dry oxidations of elder generation, 3 hours wet oxidations, last 15 minutes dry oxidations.

The chip of high-temp pressure sensor that the inventive method is made, removed the epitaxial substrate monocrystalline silicon of single-crystal silicon carbide, thereby guaranteed to realize high temperature measurement well with the monocrystalline silicon carbide technology on the insulator, and be not subjected to the influence of substrate silicon, utilize the method for bonding to realize that the making of the single-crystal silicon carbide on the insulator oxide silicon is easier, the high temperature semiconductors characteristic that helps single-crystal silicon carbide is not fully exerted.

The invention will be further described below in conjunction with accompanying drawing.

Description of drawings

Fig. 1 is that silicon chip is through the material cutaway view behind the high-temperature oxydation.

Fig. 2 has the silicon chip of silicon oxide layer and the silicon chip applying schematic diagram that another has the single-crystal silicon carbide epitaxial loayer.

Fig. 3 is behind the bonding and has corroded the material schematic diagram that silicon substrate only stays the epitaxial loayer single-crystal silicon carbide.

Fig. 4 is a pyrostat chip material structural representation.

Among the figure: 1-silicon layer (Si)

2-silicon oxide layer (SiO ₂)

3-single-crystal silicon carbide layer (SiC)

4-silicon nitride layer (Si ₃N ₄)

Embodiment

The manufacture craft process of chip of high-temp pressure sensor of the present invention is exemplified below:

1, the silicon chip to certain thickness (by the pressure range decision of transducer) carries out high-temperature oxydation, 1150 ℃ of oxidizing temperatures, and first dry oxidation 15 minutes, wet oxidation 3 hours, last dry oxidation 15 minutes, thickness of oxide layer is about 1 micron, as shown in Figure 1;

2, the silicon chip and the oxidized silicon chip of the first step that will have silicon carbide epitaxial layers cleans with the concentrated sulfuric acid, use deionized water rinsing again, wherein the silicon carbide surface of silicon chip and the oxidation silicon face of another silicon chip fit tightly together then, and sending into 1000 ℃ of soaks carried out bonding in 3 hours, as shown in Figure 2;

3, the material of the second step bonding is put into potassium hydroxide (KOH) solution and corrode, remove the silicon carbide epitaxy substrate silicon layer,, therefore stay silicon carbide epitaxial layers at last, as shown in Figure 3 because KOH does not corrode carborundum;

4, make mask with metallic aluminium (Al), make resistance full-bridge figure by lithography, go out silicon embossment resistance full-bridge with dry etching, as shown in Figure 4;

5, at surface deposition one deck silicon nitride (Si of resistance full-bridge ₃N ₄), as shown in Figure 4;

6, make lead-in wire with aluminium traditionally at last and anti-carve and alloying, so just finished the making of chip of high-temp pressure sensor.

Because silica (SiO ₂) and silicon nitride (Si ₃N ₄) the complementarity of stress, can not produce or the effect of minimum generation power carborundum (SiC) sensitive resistance that is wrapped up, so silica and silicon nitride both played the effect of insulation, can not produce the influence of non-test again to senser.

Claims

1, the manufacture method of chip of high-temp pressure sensor is characterized in that it may further comprise the steps:

(1), certain thickness silicon chip is carried out high-temperature oxydation;

(2), silicon chip and another silicon chip that has the monocrystalline silicon carbide epitaxial loayer with first step oxidation cleans with the concentrated sulfuric acid, use deionized water rinsing again, wherein the silicon carbide surface of silicon chip and the oxidation silicon face of another silicon chip fit tightly together then, and sending into 1000 ℃ of soaks carried out bonding in 3 hours;

(3), put into potassium hydroxide solution and corrode, remove the substrate silicon layer of silicon carbide epitaxy, stay silicon carbide epitaxial layers;

(4), make mask, make resistance full-bridge figure by lithography, go out silicon embossment resistance full-bridge with dry etching with metallic aluminium;

(5), at surface deposition one deck silicon nitride (Si of resistance full-bridge ₃N ₄);

(6), making lead-in wire with aluminium traditionally at last anti-carves and alloying.

2, the manufacture method of chip of high-temp pressure sensor according to claim 1 is characterized in that it is 1150 ℃ of following oxidations that said silicon chip carries out the high-temperature oxydation program, behind the 15 minutes earlier dry oxidations, and 3 hours wet oxidations, last 15 minutes dry oxidations.