JPH02228022A - Hole-pattern forming method - Google Patents

Abstract

PURPOSE:To form hole patterns having the designed sizes at the same time at the upper part and the lower part of a step by using the different masks whose correcting amounts to be applied for the designed sizes are different when the hole patterns are formed at the upper part and the lower part of the step of a substrate. CONSTITUTION:Hole patterns on masks are transferred on positive resist 21 which is applied on a substrate 31 having a step of 0.5mum by a projection expo sure method, and development is performed. At this time, the designed sizes of the diameters of the holes are both 1.0mum for the upper and lower parts of the step. Since the thicknesses of the resist film at the upper and lower parts of the step are different, the correcting amounts for the masks at the upper and lower parts of the step are made to be 0mum and +0.07mum for the designed values respectively. The masks which are differently corrected at the upper and lower parts of the step are used. In this way, the hole patterns having the designed sizes can be formed at the same time at the upper and lower parts of the step.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for forming hole patterns at the top and bottom of a step, respectively, of a substrate having a step.

[Prior Art] A hole pattern on a mask is transferred by a projection exposure method to a positive resist coated on a substrate having steps, and a development process is performed to form holes at the top and bottom of the steps of the substrate, respectively. When forming a pattern, conventionally, a mask has been used in which the amount of mask dimension correction added to the design dimension is the same for the upper and lower portions of the step.

[Problems to be Solved by the Invention] However, the above-mentioned conventional technology has the following problems.

FIG. 3 is a cross-sectional view when a positive resist 32 is applied on a substrate 31 having a step of 15 μm, and the resist film thickness 34 at the top of the step is thinner than the resist film thickness 53 at the bottom of the step. , while the lower part of the step is 1.2 μm, the upper part of the step is 17 μm.

In addition, as in FIG. 3, FIG. , is a diagram showing the relationship between the exposure time and the hole size when forming a hole pattern above and below the step, respectively, and the substrate material is silicon dioxide both above and below the step. Here, the design dimensions of the hole are 1.0 μm in diameter both on the top and bottom of the step, and the mask size correction amount is the same (0).As shown in FIG. Because the resist film thickness at the bottom is different, the relationship between the exposure time and the hole size shown in Figure 2 is thicker (different) at the top and bottom of the step. To make it
Exposure for α19 seconds is required, and at this time, the hole diameter at the bottom of the step is 0.93 μm, which is 0.07 μm smaller than the design dimension.

In this way, in the conventional hole pattern formation method, the resist film thickness is different at the top and bottom of the step, and the amount of mask dimension correction is also the same, so holes are formed on the top and bottom of the step, respectively, according to the designed dimensions. Patterns could not be formed simultaneously.

Therefore, the present invention aims to solve these problems.
The objective is to provide a hole pattern forming method that can simultaneously obtain hole patterns having the designed dimensions above and below the step.

[Means for Solving the Problems] The hole pattern forming method of the present invention involves transferring a hole pattern on a mask to a positive resist coated on a substrate having steps by a projection exposure method, and then developing it. , when forming hole patterns at the upper and lower portions of the step of the substrate, the amount of mask dimension correction added to the design dimension is different for the upper and lower portions of the step.

[Example] FIG. 1 shows a method in which a hole pattern on a mask is transferred by a projection exposure method to a positive resist coated on a substrate having a step of α5 μm, and then developed.
The lower part is a diagram showing the relationship between the exposure time and hole dimensions when forming a hole pattern, and shows the relationship between the substrate material,
Conditions such as resist coating conditions are the same as in the prior art. However, the design dimensions of the hole are 1.0 μm in diameter at both the top and bottom of the step, but the mask correction amounts for the top and bottom of the step are 0 μm and 1107 μm, respectively, with respect to the design value.
m, and masks with different corrections were used at the top and bottom of the step.

According to Figure 1, when an exposure time of 0.19 seconds is used to form a hole at the top of the step according to the design dimension, the hole size at the bottom of the step and the design dimension is caused by the difference in resist film thickness on the top and bottom of the step. Since the deviation (107 μm) was corrected in advance on the mask side, the hole diameter at the top of the step was set to 1.0 μm in diameter according to the design dimension.The exposure time was 119 seconds, and the hole diameter at the bottom of the step was also the same (as the design dimension). Diameter 1
．． It can be set to 0 μm. In this way, the amount of mask dimension correction added to the design dimension is
By using different masks at the lower part, hole patterns having the designed dimensions can be simultaneously formed at the upper and lower parts of the step.

In this example, we have described the case where the design dimensions of the hole patterns located above and below the step are both 1.0 μm in diameter. It goes without saying that even in different cases, similar effects can be obtained by performing different mask dimension corrections for the upper and lower portions of the step using the same concept as in this embodiment.

[Effects of the Invention] As described above, according to the present invention, a hole pattern on a mask is transferred to a positive resist coated on a substrate having steps by a projection exposure method, and then developed. When forming hole patterns at the top and bottom of the step of the substrate, the amount of mask dimension correction applied to the design dimension is different for the top and bottom of the step, thereby making it possible to The present invention has the effect of simultaneously forming hole patterns in accordance with the designed dimensions in the lower part, and furthermore, the present invention enables the hole patterns to be formed at the same time by simply making corrections to the mask.
Since the number of steps during hole pattern formation does not increase, it has an excellent effect in terms of manufacturing efficiency.

[Brief explanation of the drawing]

FIG. 1 shows the result when a hole pattern is formed on a substrate having steps by the hole pattern forming method of the present invention.
It is a figure showing the relationship between exposure time and hole size. FIG. 2 is a diagram showing the relationship between exposure time and hole size when a hole pattern is formed on a substrate having steps by a conventional hole pattern forming method. FIG. 3 is a cross-sectional view when a positive resist is applied onto a substrate having steps. 31...Substrate 32...Positive resist 33...Resist film thickness note at the bottom of the step 21 Katana 4...Resist film thickness at the top of the step

Claims (1)

[Claims] When forming hole patterns at the top and bottom of the step of the substrate by transferring the hole pattern on the mask using a projection exposure method to a positive resist coated on a substrate having a step and developing it. . A method for forming a hole pattern, characterized in that a mask is used in which the amount of mask dimension correction added to the design dimension differs between the upper and lower portions of the step.