JPS6031104B2 - Glass for silicon semiconductor device packaging - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel glass for silicon semiconductor device passivation.

More specifically, the present invention relates to a glass for silicon semiconductor device passivation that directly covers the joint surface of a silicon semiconductor device to stabilize and electrically protect the surface. Glass passivation technology, in which the surfaces of the joints of silicon semiconductor elements are coated and baked with powdered glass, is widely used in the manufacture of individual semiconductor elements. Conventionally, Pd○, B203, AI203, and Si are used as glasses to stabilize the joint surface of silicon semiconductor devices.
Lead glass containing 02 as main component or Zn○, B03, A
It was limited to zinc glass whose main components are I203 and Si02.

These passivation glasses generally belong to low melting point glasses, and are applied directly to the surface of silicon semiconductor devices, and the coating glass is relatively thick, several orders of magnitude thick. Hip cracking occurs and residual stress is large on the silicon semiconductor element. Therefore, in order to prevent these problems, it is necessary to use glass having a composition range close to the coefficient of thermal expansion of silicon. Therefore, the glass composition described above inevitably has a high glass softening point,
The temperature at dawn had to be as high as 600 qo or more. On the other hand, from the requirements of semiconductor device manufacturing technology, if it is possible to stabilize the surface by baking the glass at the lowest possible temperature below the alloy temperature of the aluminum electrode and silicon (approximately 570 oo) after forming the electrodes of the device,
It is possible to omit a part of the mask forming process by photolithography, etc., and it is considered that it is possible to simplify the manufacturing process of the semiconductor element and reduce the element cost.

Therefore, the inventors of the present invention have conducted intensive research to eliminate the above-mentioned drawbacks and provide a glass material that can satisfy the requirements of the manufacturing technology of semiconductor devices. We have discovered a new fact that this can be achieved, and have completed the present invention.

That is, the present invention contains Zn058 to 67 mol%, &0315
This relates to a glass for semiconductor device passivation consisting of a composition ratio of ~23 mol% and V205 and 10~27 mol%, and by using vanadium-borate-zinc glass having such a composition, the conventional method can be improved. The above-mentioned drawbacks such as glass softening temperature are low and the coefficient of thermal expansion of glass is close to that of silicon, so cracks do not occur in the coated glass.
In addition, a very remarkable effect is achieved in that the surface of the silicon semiconductor element can be well stabilized with less residual stress due to the covering glass.

In order to meet the above-mentioned demands in the manufacturing technology of semiconductor devices, the present invention is capable of coating the surface of the joint of a semiconductor device at a low temperature below the alloying temperature of an aluminum electrode and silicon (approximately 57,000 ℃), and has a stable surface. The objective is to provide a new passivation glass that can be

Next, the research results of the present inventors will be explained with reference to the drawings.

FIG. 1 is a phase diagram of the Zn○-B203-V2053 component system. According to the research results of the present inventors, Zn○ Kazuma 03
In the -V2Q three-component system, the oxide raw materials of each component constituting the vanadium-borate-zinc glass are mixed, melted, and then cooled to a supercooled state, so that the ZnO scale shown in Figure 1 is surrounded by the ZnO scale axis and the dotted line. In the composition region (component composition region to be vitrified), a glass corresponding to the component composition of the composition region is generated, and the component composition is in the direction of arrow A in the composition region that can be vitrified as shown in FIG. Glass in the composition range is stable and difficult to crystallize, while glass in the composition range in which the composition is biased in the direction of the arrowhead can be easily crystallized by heat treatment. Points A, B, C and D shown inside
Composition region surrounded by points (A point: Zn○; 67 mol%, &
03=23 mol%, V24=10 mol%, B point: Zn○
=58 mol%, B203=23 mol%, V2Q.

=19 mol%, C point: Zn○ = 58 mol%, B203=
15 mol%, V205=27 mol%, D point: Zn. D6
7 mol%, &. 32 15 mol%, V2Q 18 mol%)
The glass having the component composition (component composition of the passivation glass of the present invention) has a thermal expansion coefficient of 28×10-
A crystallized glass having a temperature of 7 to 38 x 10-7°C-1 was obtained, and it was found that this glass can be passed for direct coating of silicon semiconductor devices.

Therefore, first, an uncrystallized glass powder having a composition in the composition region surrounded by points A, B, C, and D shown in FIG. 1 is prepared, and then this glass powder is used to form a silicon semiconductor device. Apply to desired surface, 570
By heating and crystallizing at a temperature below C◯, preferably from 460 to 560 C◯, a glass coating with almost no residual stress is formed on both the silicon semiconductor element and the coating glass.

Each component constituting the silicon semiconductor device passivation glass of the present invention includes 58 to 67 mol% of Zn○.
, B205 is 15-23 mol%, V205 is 10-27
It is blended within the range of mol%. The above-mentioned components are blended in the above-mentioned composition ratios and then melted by a normal glass melting method.

The vanadium-borate-zinc glass cullet thus obtained is ground into a 325 mesh pass glass powder.
The glass powder prepared in this way is applied to the bonding surface of a silicon semiconductor device using conventional glass passivation techniques, such as centrifugal sedimentation, aerophoresis, doctor blading, and printing. It is applied directly to a thickness of several tens of peaks, approximately 460 to 5,600
It is deposited on the joint surface at a firing temperature of 0.

The coated glass thus obtained has a coefficient of thermal expansion of 28×
It is within the range of 10-7 to 38×10-7°C-1, and is suitably used as a glass for silicon semiconductor device passivation.

As stated above, the glass coating temperature (baking temperature) of the silicon semiconductor device passivation glass of the present invention is significantly lower than that of the conventional passivation glass used for surface stabilization of silicon semiconductor devices. This makes it possible to perform glass passivation at a temperature below the alloying temperature of the aluminum electrode and silicon, which can greatly contribute to the simplification of the semiconductor manufacturing process.

Next, the glass for silicon semiconductor device passivation of the present invention will be explained with reference to Examples and Comparative Examples.

Example 1 Zinc oxide (purity: 99.9% or more) 54.5% (0.6
7 mol), boric acid (Melon B03) 24.7 mol (0.2 mol) and vanadium pentoxide 23.6 mol (0.13 mol)
were dry mixed, and this mixture was filled into a platinum rubbo and melted by heating at 120,000 ℃ for 3 hours in an electric furnace in an oxidizing atmosphere (an atmosphere containing oxygen to prevent reduction of vanadium).

This melt was poured onto a steel plate at room temperature, and Zn○-803
I got a glass made of one V24. This lump glass had a softening point of 46,000 and became fluid when heated to 55,000, but crystallized when cooled. The obtained lump glass was crushed while carefully preventing the contamination of impurities, and then divided into sections to obtain a glass powder with a 325 mesh pass.

This glass powder was applied to the surface of a silicon semiconductor element in a thickness of 3 layers by a conventionally known coating method, and then baked at 550° C. for 20 minutes to complete the crystallized glass coating.

The resulting coated glass has a thermal expansion coefficient of 35 x 10-7°C.
1, and the insulation resistance was 5 x 1 and 20 -.
Table 1 shows the component composition and physical properties of the glass obtained.

Example 1 Zinc oxide (mentioned above) 54.5 moles (0.67 moles), boric acid 19.8 moles (0.16 moles), vanadium pentoxide 30.9 moles (0.17 moles) Glass powder was obtained by heating, melting, and pulverizing in the same manner as described above.

This glass had a softening point of 420 qo, became fluid at 520 oo, and crystallized by cooling. This glass powder was applied to the surface of a silicon semiconductor element in the same manner as in Example 1, and fired at 52,000 for 20 minutes to complete coating with crystallized glass.

The resulting coated glass has a thermal expansion coefficient of 37xlo-7℃-
1, and the insulation resistance was 2×1 and 201 cm. Table 1 shows the component composition and physical properties of the glass obtained.

Example 3 Zinc oxide (mentioned above) 52.1 mol (0.64 mol), boric acid 19.8 mol (0.16 mol), vanadium pentoxide 30.9 mol (0.17 mol) in Example 1 Glass powder was obtained by heating, melting, and pulverizing in the same manner as described above.

This glass had a softening point of 410 qo, became fluid at 50,000 qo, and crystallized by cooling. This glass powder was applied to the surface of a silicon semiconductor element in the same manner as in Example 1, and fired at 50,000 for 20 minutes to complete coating with crystallized glass.

The resulting coated glass has a thermal expansion coefficient of 31 x 10-7℃.
1, and the insulation resistance was 5×1 and 20 arcs. Table 1 shows the component composition and physical properties of the glass obtained.

Examples 4 to 10 Zinc oxide (mentioned above), boric acid and vanadium pentoxide were heated and melted and ground in the same manner as in Example 1 to obtain glass powder having the composition shown in Table 1.

The obtained glass powder was coated on the surface of a silicon semiconductor element in the same manner as in Example 1 and fired at the firing temperature shown in Table 1. All of the glass powders could be coated at a low temperature of 57,000 ml or less, and crystallization did not occur. Glass coating was completed.

Table 1 shows the component composition and physical properties of the glass obtained.

For comparison, glass powders having the component compositions shown in Comparative Examples 1 to 3 in Table 1 were produced in the same manner as in Example 1. Table 1 shows the component composition and physical properties of these glasses. Table 1 From Table 1, it can be seen that the glass for silicon semiconductor device passivation of the present invention has a smaller coefficient of thermal expansion and higher insulation resistance than the glass having the composition of the comparative example, and has a lower thermal expansion coefficient and a higher insulation resistance. It is extremely useful as glass for ventilation.

In addition, with the glass having the component composition shown in Comparative Example 1, crystallized glass cannot be obtained and the coefficient of thermal expansion is large, and with the glass having the component composition shown in Comparative Examples 2 and 3, although crystallized glass can be obtained. On the other hand, the coefficient of thermal expansion increases, and the insulation resistance decreases due to the increase in the vanadium component, both of which are unsuitable as a passivation glass for silicon semiconductor devices.

[Brief explanation of the drawing]

FIG. 1 is a phase diagram of the Zn○-&03-V243 component system. 1 figure

Claims (1)

[Claims] 1 ZnO 58-67 mol%, B_2O_315-23
A glass for silicon semiconductor device packaging having a composition ratio of mol% and V_2O_510 to 27 mol%.