An anti-irradiation glass powder for mesa-type glass-passivated chips and a preparation method thereof

Abstract

The present invention discloses an anti-irradiation glass powder for mesa-type glass passivated chips and a preparation method thereof, belonging to the technical field of materials used in the semiconductor industry. Its components are composed of ZnO, B2O3, SiO2, Ta2O5, PbO, Si3N4, and A (A = Sb2O3 + CeO2 + WO3 + Nb2O5). The mass percentage content of each component is 40-65% ZnO, 18-29% B2O3, 5-16% SiO2, 1-5% Ta2O5, 2-8% PbO, 0.3-3% Si3N4, and 1-8% A (A = Sb2O3 + CeO2 + WO3 + Nb2O5). The anti-irradiation passivation glass powder prepared by the present invention has a lower sintering temperature and good anti-irradiation effect, and at the same time has a lower expansion coefficient and good crack resistance, and has excellent passivation effect.

Description

Technical Field

[0001] The present invention belongs to the technical field of materials for the semiconductor industry, and particularly relates to an anti-irradiation passivation glass powder for mesa-type glass passivated chips and a preparation method thereof. Background Art

[0002] Anti-irradiation glass is a special optical glass with a small decrease in visible light transmittance after being irradiated by strong rays. The charged radiation particles in the aerospace space environment mainly include heavy ions, electrons, protons, X-rays, etc. These charged particles have a strong impact on the performance of aerospace power devices. They interact with the devices in the environment, generating ionization radiation effects, single particle effects, displacement radiation effects, etc., resulting in serious consequences of device failure. Therefore, the reliability of power devices is very important.

[0003] By optimizing the chip process and packaging structure, the anti-irradiation ability of the device can be improved. However, for mesa-type glass passivated diodes, the processing quality of the chip mesa not only affects the inherent reliability of the device itself, but also plays an extremely important role in the anti-irradiation ability of the device. When the device is bombarded by high-energy particles during operation, electron-hole pairs will be generated. Under the action of an electric field, the electron-hole pairs generate an instantaneous current I S , at this time, the current passes through the weak link of the chip mesa, forming a current channel, which increases the surface leakage current and deteriorates, and even burns out the device in severe cases. Summary of the Invention

[0004] The present application provides an anti-irradiation glass powder for mesa-type glass passivated chips and a preparation method thereof, which can achieve further reinforcement of the anti-irradiation ability of the device without reducing the passivation effect of the mesa-type glass passivated chip, so as to solve the problem that due to irradiation, there are weak links on the chip mesa, and when the current passes through, a current channel is formed, increasing the surface leakage current and deteriorating, and even burning out the device. At the same time, the anti-cracking performance after encapsulation of the glass powder can be improved.

[0005] The technical solution of the present invention is: an anti-irradiation passivation glass powder, the mass percentage composition of which is: 40-65% ZnO, 18-29% B 2 O 3 、5-16% SiO 2 、1-5% Ta 2 O 5 、2-8% PbO, 0.3-3% Si 3 N 4 、1-8% A, wherein A is a composition of four of Sb 2 O 3 、CeO 2 、WO 3 、Nb 2 O 5 。

[0006] Preferably, the mass percentage of Ta 2 O 5 is 2-4%.

[0007] Preferably, the mass percentage of PbO is 2-7%.

[0008] Preferably, the mass percentage of Si 3 N 4 is 0.4-1%.

[0009] Preferably, the mass percentage of A is 1-2%, and the content of the single element oxide does not exceed 0.55%. Exceeding 0.55% will lead to aggravated glass encapsulation cracking and a decrease in the anti-irradiation effect, affecting the overall performance.

[0010] A is a composition of Sb 2 O 3 , CeO 2 , WO 3 , Nb 2 O 5 The mass percentage composition is: 0.15-0.3%, 0.4-0.55%, 0.2-0.4%, 0.2-0.55%.

[0011] The sintering temperature of the glass powder is 650-700 °C, and the thermal expansion coefficient is 38-43×10 -7 / °C.

[0012] The preparation method of the passivation glass powder includes the following steps: Weigh each raw material according to the mass percentage and mix them evenly. Add the mixture into a platinum crucible with a lid, and place the crucible in a lifting resistance furnace for heat preservation and melting. The melting temperature is 1250-1350 °C, and the heat preservation time is 40-60 minutes. Pour the melted glass liquid into a pure water bucket for water quenching treatment to form glass particles. Add the glass particles into a ball mill for pulverization, and obtain glass powder with a particle size D50 of 2-3.5 μm after filtration, drying, and screening.

[0013] Preferably, the particle size D50 is 2.3-2.7 μm.

[0014] Preferably, keep the sieved powder in a chain furnace at 450-530 °C for 30-60 minutes, and take it out after cooling to obtain the finished glass powder.

[0015] The beneficial effects of the present invention: In the anti-irradiation passivation glass powder for a mesa-type glass passivated chip of the present invention, various element compounds are added: Ta 2 O 5 , PbO, Si 3 N 4 , Sb 2 O3 , CeO 2 , WO 3 , Nb 2 O 5 , Si 3 N 4 The coefficient of thermal expansion is 2.8 - 3.2×10 -6 / °C, the flexural strength is 147 Mpa, and Si 3 N 4 The coefficient of thermal expansion is for good matching with the silicon wafer, without cracking or shrinking; the flexural strength is for the glass powder not to crack and have impact resistance in a harsh environment, and at the same time have excellent passivation effect and radiation resistance; Ta 2 O 5 The coefficient of thermal expansion is 0.55×10 -6 / °C, with a low expansion coefficient and good chemical stability, which can reduce the glass expansion coefficient and at the same time promote the glass system to have good mechanical strength and thermal shock resistance; PbO as a flux can reduce the melting temperature and softening temperature of the glass, and is also a good radiation-resistant material; Sb 2 O 3 , CeO 2 , WO 3 , Nb 2 O 5 The first function of is to clarify and reduce the generation of glass defects; the second is to be a space radiation-resistant glass stabilizer to improve the radiation stability of the glass and cope with the strong radiation of various high-energy particles, electrons, protons, etc. in space. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic diagram of the product structure of the glass powder prepared by the present invention for Si chips; DETAILED DESCRIPTION OF THE INVENTION

[0017] The technical solution of the present invention will be further described in detail below through examples, which are explanations rather than limitations of the present invention.

[0018] By mass percentage, 40 - 65% ZnO, 18 - 29% B 2 O 3 , 5 - 16% SiO 2 , 1 - 5% Ta 2 O 5 , 2 - 8% PbO, 0.3 - 3% Si 3 N 4 , 1 - 8% A, where A is Sb 2 O 3 , CeO 2 , WO 3 , Nb 2 O5 A composition of four components, with the mass percentage composition being: 0.15 - 0.3: 0.4 - 0.55: 0.2 - 0.4: 0.2 - 0.55. Weigh each raw material and mix them evenly. Add this mixture into a platinum crucible with a lid, and place the crucible into a lift-type resistance furnace for heat preservation and melting. The melting temperature is 1250 - 1350 °C, and the heat preservation time is 40 - 60 min. Pour the melted glass liquid into a pure water bucket for water quenching treatment to form glass particles. Add the glass particles into a ball mill for pulverization, and after filtration, drying, and screening, obtain glass powder with a D50 particle size of 2 - 3.5 um. The mass ratios of Examples 1 - 6 are shown in Table 1:

[0019] Table 1 Component Ratios of Each Example

[0020]

[0021] In Example 1, when the content of any one component of the composition of Sb 2 O 3 , CeO 2 , WO 3 , and Nb 2 O 5 increases to more than 0.55%, and the increased part is correspondingly reduced by the component of ZnO, problems such as a decrease in the anti-irradiation performance compared to Example 1 and a decrease in the pass rate of the anti-cracking performance will occur.

[0022] The anti-irradiation performance and anti-cracking performance of the examples and comparative examples are shown in the following table (the anti-irradiation performance is characterized by spectral characteristics, with the unit of transparency ratio %):

[0023]

[0024]

[0025] The schematic diagram of the product structure of the glass powder prepared by the present invention for use in Si chips is shown in Figure 1 . The glass anti-cracking experiment of this product is carried out according to Method 1057: Glass Anti-Cracking Property in GJB128B - 2021 "Test Methods for Semiconductor Discrete Devices". Immerse and take out in a thermal bath for 25 cycles, and the pass rate is 100%. The sample size placed in each experiment of this application is 50 - 100.

[0026] Keep the sieved powder obtained in Example 1 in a chain furnace at 450 - 530 °C for 30 - 60 minutes, and take it out after cooling to obtain the finished glass powder. The inventor unexpectedly found that after 100 cycles of the glass anti-cracking experiment, the pass rate was still 100%. However, after the glass powder obtained in Example 1 was made into a product for Si chips, after 100 cycles of the glass anti-cracking experiment, the pass rate was 90 - 95%, and there would be 4 - 10 cases of cracking on the surface of the coated glass in a batch of samples.

[0027] The above content is a further detailed description of the present invention in combination with specific embodiments. It cannot be determined that the specific implementation of the present invention is only limited to these descriptions. For those of ordinary skill in the technical field to which the present invention pertains, without departing from the concept of the present invention, several simple deductions or substitutions can still be made, and all should be regarded as falling within the protection scope determined by the claims submitted for the present invention.

Claims

1. A radiation-resistant passivation glass powder, characterized in that, Its mass percentage composition is: 40 - 65% ZnO, 18 - 29% B 2 O 3 、5 - 16% SiO 2 、1 - 5% Ta 2 O 5 、2 - 8% PbO, 0.3 - 3% Si 3 N 4 、1 - 8% A, where A is a composition of Sb 2 O 3 、CeO 2 、WO 3 、Nb 2 O 5 a composition of four kinds, and the A is Sb 2 O 3 、CeO 2 、WO 3 、Nb 2 O 5 a composition of four kinds, and the mass percentage composition is: 0.15 - 0.3%, 0.4 - 0.55%, 0.2 - 0.4%, 0.2 - 0.55%.

2. The passivation glass powder according to claim 1, characterized in that, The Ta 2 O 5 has a mass percentage of 2 to 4%.

3. The passivation glass powder according to claim 1, characterized in that, the mass percentage of PbO is 2-7%.

4. The passivation glass powder according to claim 1, characterized in that, The Si 3 N 4 has a mass percentage of 0.4 to 1%.

5. The passivation glass powder according to any one of claims 1-4, characterized in that, The sintering temperature of the glass powder is 650 to 700 °C, and the thermal expansion coefficient is 38 to 43×10 -7 / °C.

6. The preparation method of the passivation glass powder according to claim 5, characterized in that, comprises the following steps: Weigh each raw material according to the mass percentage and mix them evenly. Add the mixture into a platinum crucible with a lid, and put the crucible into a lifting resistance furnace for heat preservation and melting. The melting temperature is 1250-1350 °C, and the heat preservation time is 40-60 min. Pour the melted glass liquid into a pure water bucket for water quenching treatment to form glass particles. Add the glass particles into a ball mill for pulverization, and obtain glass powder with a particle size D50 of 2-3.5 um after filtration, drying and screening.

7. The preparation method of the passivation glass powder according to claim 6, characterized in that, the particle size D50 is 2.3-2.7 um.

8. The preparation method of the passivation glass powder according to claim 6, characterized in that, Keep the sieved powder in a chain furnace at 450-530 °C for 30-60 minutes, and take it out after cooling to obtain the finished glass powder.

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