JPS6071540A - Glass for photomask substrate - Google Patents

Abstract

PURPOSE:To obtain the titled glass having low coefft. of thermal expansion, high yield temp., superior stability, chemical durability, transmissivity for ultraviolet rays, and fusibility by specifying a compsn. by adding BaO to SiO2-B2O3-Al2O3- MgO-ZnO-PbO glass. CONSTITUTION:The titled glass contains 45-60wt% SiO2; 0.5-12% B2O3;10- 22wt% Al2O3; 5-17wt% MgO; 0-5wt% CaO; 0-8wt% SrO; 1.5-15wt% BaO; 1.5-17wt% ZnO; 0.5-10wt% PbO; wherein ZnO+PbO is >=6wt%; Ta2O5+ Nb2O5+La2O3+Gd2O3+Y2O3+WO3 is 0-7wt%; ZrO2+TiO2 is 0-5wt%; Na2O+ K2O+Li2O is 0-2wt%; As2O3 8s 0-0.5wt% and Sb2O3 is 0-0.5wt%. The coefft. of thermal expansion is (ca.27-40)X10<7>/ deg.C at 100-300 deg.C; the yield temp. is >=ca.750 deg.C. The glass has superior heat resistance and fire resistance with also superior stability, chemical durability, transmissivity for ultraviolet rays, and fusibility.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a thermal expansion coefficient (αX 107/'01100~
300°C) is in the range of approximately 27 to 40°C, and the yield temperature is approximately 750°C or higher, providing excellent heat and fire resistance, as well as excellent stability, chemical durability, and ultraviolet transmittance. 5iOz-820+-A]zO with improved properties
The present invention relates to a glass suitable for use as an a-MgO-Ban-ZnO-PbO-based photomask substrate material.

In recent years, glass has been widely used in members used in the electronic industry such as IC substrates, IC photomasks, and stripe filters. However, among these, IC photomasks, that is, photomask substrates used in the IC manufacturing process using the photoetching method, are free from bubbles, striae, and inclusions, as well as a low coefficient of thermal expansion, which increases the degree of IC integration. In addition, heat resistance and fire resistance that will not be damaged or softened or deformed even during heat cycles in metal vapor deposition processes, chemical durability against cleaning and etching with various chemicals, ultraviolet transparency, and integrated circuit compatibility. It is also necessary that the shaped metal vapor deposited film has excellent properties such as adhesion.

However, as glass traditionally used for the above purposes,
It is inferior to Pyrex-type alkali borosilicate glass, and has a yield point of about 650°C, meaning it does not have good fire resistance. Various types of calcium-aluminosilicate glasses such as fiber mmE glass and fire-resistant glass are also known, but these glasses require a relatively high content of CaO, so their meltability is low. Although it will be improved,
The coefficient of thermal expansion is about 42 to 65, which is too high, and therefore, the degree of integration of the IC cannot be increased, and the heat resistance is poor.

Therefore, the present inventors previously applied for patent application No. 57-224957.
In the issue, a new SiO□-8203-Al1[]]
We proposed a 3-MgO-ZnO-PbO glass. However, although this glass has a small coefficient of thermal expansion, in order to maintain stability, the amount of components that promote glass melting is actually -
H. Since the amount is limited, it cannot be said that the meltability is sufficient as a glass for photomask substrates. In order to particularly improve the meltability of this glass, it is necessary to add a relatively large amount of expensive rare earth elements such as La2O3 or 5b20+.

Also, S 1o2-A 1203-CaO-MgO-Z
nO-PbO glass is known from JP-A-58-32038 and JP-A-58-41738, but since it is necessary to contain a large amount of CaO component to maintain the stability of the glass, the calcium-alumino Like silicate glass, it has an excessive coefficient of thermal expansion.

The purpose of the present invention is to comprehensively improve the various drawbacks of the above-mentioned glass, and to maintain the above-described low thermal expansion, high yield temperature characteristics, excellent stability, chemical durability, and ultraviolet transmittance. At the same time, it is an object of the present invention to provide a glass for photomask substrates having even better melting properties.

In order to achieve this objective, the present inventors conducted intensive test research and found that the above 5i02-B203-A I
203-Introducing BaO as an essential component into MgO-ZnO-PbO glass improves the stability of the glass while lowering the coefficient of thermal expansion compared to the case of introducing CaO, which is essential for ordinary fire-resistant glasses. We have found that it is possible to further improve the Furthermore, as a result, it was found that the content of components exhibiting a fluxing agent effect in glass, that is, ZnO and PbO components, could be significantly increased. The present invention was completed based on this knowledge.

The characteristics of the composition of the glass for photomask substrate of the present invention are: 5iOz 45-60%, 82030.5-12% by weight
%, Al2O3 10-22%, Mg05-17%, Ca
O0-5%, Sr0 0-8%, Ban 1.5-15
%, ZnO1.5-17%, Pb00.5-10%, however, ZnO+PbO≧6%, Ta205+Nb2O5
+La2O3+Gd20s +Y2O3+Bi2O3+
WO30-7%, ZrO2+ TiO20-5%, Na
20+Li2O0~2.5%, As203o to 2O+
~0.5% and 5b2030~0.5%.

In the glass of the present invention, the reason why the content range of each component is limited as described above is as follows. That is, although the SiO2 component has the effect of improving the heat resistance and chemical durability of glass, it must be contained in an amount of 45% or more in order to achieve the object of the present invention. However, if the amount exceeds 60%, the meltability deteriorates and it becomes difficult to obtain homogeneous glass.

The B2O3 component is a necessary component because it increases the meltability of glass, but if its amount is less than 0.5%, the above effect will not appear, and if it exceeds 12%, the yield temperature of the glass will be low, and the melting At this time, the amount of B2O3 volatilized increases, making the composition more likely to fluctuate.

The amount of Al2O3 component needs to be 105 or more in order to obtain the desired fire resistance while preventing the phase separation tendency of the glass, but if the amount exceeds 22%, the meltability of the glass will deteriorate.

The MgO component has the effect of increasing the meltability of the glass without increasing the thermal expansion coefficient, but if the content is less than 5%, the effect cannot be expected to be sufficient, and if the content exceeds 17%, the glass is likely to devitrify. Become.

Each component of CaO and SrO has the effect of improving the meltability of glass and can be added arbitrarily, but unlike the BaO component described below, these components do not only increase the coefficient of thermal expansion of glass but also cause phase separation. The effect of suppressing crystallization is also small. Therefore, the amounts of these components should be kept within 5% and 8%, respectively.

In the present invention, the BaO component is an important component that has been found to have the effect of stabilizing the glass by preventing the tendency of phase separation and crystallization without increasing the coefficient of thermal expansion of the glass. However, if the amount of BaO component is less than 1.5%, the effect is not significant, and if it exceeds 15%, the meltability of the glass tends to deteriorate. The drawings listed at the end are 5i
(h 53%, 82037%, Al2O315%, Mg
When BaO and CaO components are added to the basic composition of 0.012%, Zn08%, and PbO5%, respectively, and glass is obtained in the same manner as in each example described later, the thermal expansion coefficient and stability of the glass vary depending on the amount added. 4. In the case of Ban addition, compared to CaO, the coefficient of thermal expansion of the glass does not become excessive, and it shows a remarkable stabilizing effect even with a small amount, and shows that the stabilization region is wide. There is.

The ZnO component is an important component because it has the effect of improving the meltability, chemical durability, and polishability of glass.
When the amount is less than 1.5%, these effects are not significant, and when it exceeds 17%, the glass tends to devitrify.

In the glass of the present invention, the PbO component is an important component because it has the effect of improving meltability and preventing a tendency to devitrify, but if the amount of the PbO component is less than 0.5%, the effect is not sufficient. Moreover, if it exceeds 10%, the chemical durability of the glass deteriorates, which is not preferable.

In the glass of the present invention containing BaO, as mentioned above, it is possible to increase the content of ZnO and PbO components having a fluxing agent effect while preventing the tendency of devitrification. The total amount of the PbO component must be 6% or more in order to improve the meltability of the glass.

Ta205, Nb2O5, La20a, Gdz
03. Each of the components Y2O3, Bi2O3, and l1i03 has the effect of lowering the coefficient of thermal expansion of glass and increasing the melting properties, so they can be added arbitrarily as necessary, but one or two of these components can be added. The total amount of seeds is 7
% or less is appropriate.

Each component of ZrO2 and TiO2 improves the chemical durability of the glass, and the latter has the effect of improving meltability and devitrification, so it can be added arbitrarily, but one or both of these components may be added. A total amount of seeds of up to 5% is sufficient.

In order to maintain low thermal expansion, the total amount of one or two of these components is preferably 2.5% or less,
In addition, as part of the total amount of these components, the LizO component is 0.
．． Up to 5% may be used.

Each component of Ag2O3 and 5b203 can be optionally added up to 0.5% each as a refining agent during glass melting.

Next, practical composition examples of the glasses of the present invention will be described based on the linear expansion coefficient (α (lOo - 30oC) x 107), yielding point (At), water resistance value (RW (P)) and acid resistance value ( RW(P)); (particle size 420-590 p-
(7) Weight loss of the crushed grains after immersing them in distilled water if they are water-resistant or in a 0.01N nitric acid aqueous solution if they are acid-resistant and treating them in a boiling water bath for 60 minutes ( WT%)], ultraviolet transmittance (Tuv (%)) [
Sample thickness 10m111, measurement wavelength; 3401111
Table 1 shows the measurement results for the glass temperature (T('O)) at the viscosity of 1) and 103 voids.

(The following is blank space) Table 1 shows the above-mentioned patent application filed in 1983. Comparative examples (No, I and Flk) of the glass shown in No. 724957,
II). The 4-glass measurement test samples listed in Table 1 were all used for the purpose of testing phase separation emulsivity.
After the melt-fining step, 900'0. It was obtained by heat treatment for 20 minutes and then cooling.

Note that the value of α of glass changes depending on the measurement temperature range, but for aluminosilicate glasses including the glass of the present invention, the measurement temperature range is (100 to 300℃).
), for example, in the case of (50 to 200°C), α generally shows a value about 3 to 5 lower. Therefore, the value of α of the glass of the present invention is set within a relatively high temperature range.

As seen in Table 1, the glasses of the examples of the present invention are:
Stable and transparent without phase separation or crystallization,
It has excellent UV transparency, water resistance and acid resistance. In addition, the glass of the example of the present invention has a very low linear expansion coefficient in the range of 28 to 40, and at the same time has a yield point of more than about 750°C, and has excellent heat resistance and fire resistance. .

Furthermore, in all of the first glasses of the present invention, the total amount of ZnO and PbO components is increased by introducing the BaO component, so even though they are alkali-free or low alkali-containing glasses, they have low meltability. It has a high improvement effect. The temperature of the glass at the viscosity of lO bois is 1 for the glasses of Comparative Examples No. I and No. II, respectively.
000°C and 1430°C, but the glasses of Example teeth 1 to Il&) and 5, which have α values comparable to those of the glass of the comparative example, were heated to 1300°C, 1330°C, and 1350°C, respectively.
C, 1310° C. and 1320° C., the glasses of the examples of the invention are generally more meltable than the other examples, and the homogenization operation is advantageous.

The glass for photomask substrates of the present invention is produced by weighing and mixing raw materials such as oxides, carbonates, and nitrates so as to obtain a predetermined oxide glass composition, and then heating the mixture at a temperature of about 1350 to 1450°C using ordinary glass manufacturing equipment. It can be obtained by degassing and homogenizing it, molding it into a desired shape, and cooling it, but it has the advantage that the raw material to be weighed is relatively inexpensive in improving meltability.

As described in H below, the glass for photomask substrate of the present invention has a specific composition range of 5i02-BzO3-Al203-
Since it is MgO-BaO-ZnO-PbO glass,
In addition to low thermal expansion, heat and fire resistance, devitrification resistance,
Not only does it have excellent chemical durability, ultraviolet transmittance, electrical insulation, and adhesion of metal-deposited films, but it also improves melting properties, making it possible to produce homogeneous products with even higher yields. Can be manufactured economically. Therefore, it is useful as a glass for photomask substrates, and is also suitable for use as electronic components such as stripe filters that require the above characteristics.

[Brief explanation of the drawing]

Figure 1 shows Si02-8203-ASi02-8203
FIG. 2 is a comparison diagram showing the effects on the linear expansion coefficient and stability of the glass when BaO and CaO are respectively added to the -Al203- based base glass. In the figure, A shows the case of BaO addition, B shows the case of CaO addition,
The mark e indicates a devitrified state, and the mark ○ indicates a transparent state. Patent applicant Teatsu Optical Glass Manufacturing Co., Ltd. Ingredient addition amount (%)

Claims (1)

[Claims] In weight%, 5i0245-80%, B2030.5-12%, A120310-22%, M
805-17%, Ca0 0-5%, Sr0 0-8
%, Ba0 1.5-15%, ZnO 1.5-17%
, Pb0 0.5-10%, however, ZnO + Pb0
56%, TazOs-1-Nb 205-1-La20
s +Gd2O3+YzOs+Bi2O3+WO30~
7% ZrO2+Tio□O~5%, 20 to Na2O+
+LizOO~2.5%, Ag2O3070.5% and 5b2030~0.5%. Glass for photomask substrates.