JPS61226931A - Manufacture of passivation glass and semiconductor device using the same - Google Patents

Abstract

PURPOSE:To obtain a passivation film of high resistance and high voltage resistance, by making lead oxide, silicon oxide, boron oxide, aluminum oxide and arsenic oxide be contained in a specific ratio and by making the content of a hydroxide base or water in glass be a specified value or below, so as to fluidize the glass in a low-temperature process. CONSTITUTION:Passivation glass is made to contain lead oxide (PbO) 30-55%, silicon oxide (SiO2) 20-45%, boron oxide (B2O3) 5-30%, aluminum oxide (Al2O3) 1-7% and arsenic oxide (As2O3) 0.01-3% in the weight ratio, while the content of a hydroxide base (OH base) is made to be 500ppm or below. Although the lead oxide acts to lower the fluidization temperature of the glass, it is little effective when it is 30% or below in said ratio, and the glass tends to lose the transparency when it is 55% or above. In order to increase a voltage resistance, it is necessary that the OH base remains little in the glass, and this is enabled by melting the glass in an oxidizing atmosphere or by sending dry air into the melt thereof for bubbling.

Description

[Detailed Description of the Invention] [Technical Field to which the Invention Pertains] The present invention relates to a glass for noyassipation and a method for manufacturing a semiconductor device using the same, and relates to a method for manufacturing a semiconductor device that is stable and has a high breakdown voltage. The present invention relates to a glass for insulation and a method of manufacturing a semiconductor device using the same.

[Technical background of the invention and its problems]

Passivation films are used to stabilize the electrical characteristics of semiconductor surfaces and protect devices from the effects of the external atmosphere, especially in highly integrated ultra-large semiconductor integrated circuits (ultra LS).
It is particularly important in semiconductor devices having minute circuits such as I).

Conventionally, PSG (phosphoric acid silica thread glass) has been widely used as passivation glass for semiconductor devices. However, this PSG had a very high fluidization temperature of 1050° C. and had insufficient water resistance due to the phosphoric acid contained in the glass. Furthermore, since the PSG film is deposited by the CVD method, productivity is good, but the film thickness is at most 1.
It was about μm. Because of these drawbacks, it has not been particularly applicable to devices requiring low-temperature processes.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a passivation film that can be fluidized and formed into a film in a low-temperature process, has high resistance, and has a high breakdown voltage.

[Summary of the invention]

In order to achieve the second object, the passivation glass of the present invention contains 30 to 55% lead oxide (PbO) by weight.
, silicon oxide (Sin2) 20-45%, boron oxide (B203) 5-30%, aluminum oxide (Al2)
O. ) 1-7%, arsenic oxide (As2o, ) 0.0
1 to 3, and the content of water or hydroxyl groups (OH groups) is 500 ppm or less.

In addition, the method for manufacturing a semiconductor device of the present invention includes, by weight, 30 to 55% lead oxide, 20 to 45% silicon oxide, 5 to 30% boron oxide, 1 to 7% aluminum oxide, and 0 arsenic oxide.
．． Contains 01 to 3 groups and also contains water or hydroxyl group (OH group)
A passivation film is formed by coating a semiconductor device with glass having a content of 500 ppm or less and fluidizing and solidifying it in an oxidizing atmosphere.

Here, lead oxide has the effect of lowering the fluidization temperature of the glass, but if the coefficient is less than 30, the effect is small, and if it is more than 55, the glass tends to devitrify.

In addition, silicon oxide is a glass-forming oxide, but it is impossible to vitrify at temperatures below 20%, and when it is above 45%, the fluidization temperature exceeds 900°C, making it practically unusable for semiconductor devices. It's for a reason.

Boron oxide helps with vitrification and increases acid resistance, but if it is less than 5 parts, its effect is small, and if it is more than 30 parts, the fluidization temperature increases and it becomes virtually unusable for coating semiconductor devices. .

Furthermore, aluminum oxide is an anti-devitrification agent, but 1
This is because if the temperature is lower than 7, the effect will be small, and if it is higher than 7, the melting point of the glass will rise significantly and it will be difficult to melt the glass.

Further, arsenic oxide is a clarifying agent, and if it is less than 0.01, it has no effect, and if it is more than 3, the homogeneity and fluidity of the glass will deteriorate.

Furthermore, the content of water or hydroxyl groups in the glass is 5 n o
If it exceeds ppm, the withstand voltage of the device deteriorates. Therefore, in order to increase the pressure resistance, it is necessary that the residual OH groups in the glass be small, but this can be done by melting in an oxidizing atmosphere or bubbling dry air into the molten melt. It is possible to reduce the amount to 500 ppm or less.

Furthermore, by fluidizing and solidifying the glass in an oxidizing atmosphere, /4? As a result, the lead oxide in the glass is reduced to metallic lead and remains in the glass as lead oxide, maintaining high resistance without reducing the resistivity of the glass. be able to.

(When fluidized and solidified in a reducing atmosphere, lead oxide turns into metallic lead and loses its function as a passivation film.)
[Effects of the Invention] According to the pad page and glass of the present invention, the fluidization temperature is low and it can be formed into a film in a low-temperature process, and it also has high resistance.

Further, according to the method of the present invention, it is possible to form a passivation film with a high breakdown voltage.

[Embodiments of the invention]

Embodiments of the present invention will be described in detail below with reference to the drawings.

The figure shows an N+N-P+ type diode according to the present invention.
An example is shown in which the glass is coated with glass 1 for sewage. 2 is N
+N""P+ type silicon layer, 3 is an anode, and 4 is a cathode.

(Example 1) By mixing 44% lead oxide, 35% silicon oxide, 15% boron oxide, 5% aluminum oxide, and 1.0% arsenic oxide by weight, the mixture was heated and melted in a platinum crucible. forms a lath.

After this, dry air was introduced into the platinum melt through a molecular sieve and an aluminum oxide pipe, and the
Bubble for a minute.

The fluidization temperature of the glass thus formed is Tf=
The temperature was 600 DEG C., and the specific resistance was ρ=IX10""Ω"cm.0 This glass was powdered, and a solvent was added to make it yeast-like, and the glass in the form of a single stroke was applied to the Dio-P.

Thereafter, the glass is heated to 650° C. in an oxidizing atmosphere to fluidize and solidify the glass to form a sintering film with a thickness of about 3 μm.

The diode 9 formed in this way has a breakdown voltage of 900
It was v.

(Example 2) 35% lead oxide, 33% silicon oxide, 26% boron oxide, 4% aluminum oxide, and 1.5 parts arsenic oxide were mixed by weight, and heated and melted in the same manner as in Example 1. After vitrification, bubbling is performed for 30 minutes.

The fluidization temperature of the glass thus formed is Tf=
At 600°C, the specific resistance was ρ=5×10 Ω·saw.

This glass was made into a paste as in Example 1,
After being applied to the diode, it is fluidized and solidified in an oxidizing atmosphere at 650° C. to form a passivation film of about 2.5 μm.

The diode P thus formed has a breakdown voltage of 850V.
Met.

(Example 3) 45% lead oxide, 25% silicon oxide, 24% boron oxide, 5% aluminum oxide, and 1 part arsenic oxide were mixed by weight and heated and melted in the same manner as in Examples 1 and 2 to form glass. After bubbling for 30 minutes.

The fluidization temperature of the glass thus formed is Tf=
560℃, the specific resistance was ρ = IX10 Ω・α. This glass was made into a paste and applied to the diode in the same manner as in Examples 1 and 2, and then fluidized and solidified in an oxidizing atmosphere at 650℃. A passivation film with a thickness of at least about 3.5 μm was formed.

□How is the suppression of the diode formed 900?
It was V.

The passivation glass of the present invention has fewer hydroxyl groups and fewer air bubbles, so it has less leakage than normal glass, and is suitable for use not only in diodes, but also in ceramic coatings for LSIs, welded glass for packages, etc. Of course, it can also be used.

[Brief explanation of drawings]

The figure shows an example of a device having an insipation film. 111. Passivation glass, 2... silicon layer, 3... anode, 4... cathode.

Claims (2)

[Claims] (1) Lead oxide (PbO) 30-55%, silicon oxide (SiO_2) 20-45%, boron oxide (B_
2O_3) 5-30%, aluminum oxide (Al_2O
_3) 1-7%, arsenic oxide (As_2O_3) 0.01
It contains ~3% of hydroxyl groups (
1. A passivation glass characterized by containing 500 ppm or less of water or OH groups. (2) Lead oxide (PbO) 30-55%, silicon oxide (SiO_2) 20-45%, boron oxide (B_
2O_3) 5-30%, aluminum oxide (Al_2O
_3) 1-7%, arsenic oxide (As_2O_3) 0.01
~3% and hydroxyl group (OH group) or water content is 5%.
1. A method for manufacturing a semiconductor device, comprising the steps of: coating the surface of a semiconductor device with glass having a concentration of 00 ppm or less; and fluidizing and solidifying in an oxidizing atmosphere.