JPH08248613A - Etching photographic mask and its using method - Google Patents

Abstract

PURPOSE: To reduce the kind of photomasks for parts made of silicon or glass which is etching-processed. CONSTITUTION: When the front and back patterns of a substrate are same mutually, the A mark 1a and B mark 1b of the matching mark of a shallow dig mask 1 are positioned at line symmetric positions with respect to the center line of the line symmetry of the pattern when the front and back patterns of the substrate is seen through, and the A mark 2m and B mark 2n of the matching mark of a deep dig mask 2 are positioned at reverse positions to the shallow mask 1. A photoresist-stuck substrate 13 is disposed there so as to expose, and after an altered position is removed in another device, etching is conducted. The A mark 2m and B mark 2n of the matching mark of the deep dig mask 2 are positioned on a substrate 13a to which the photoresist is again stuck, and the substrate 13a is processed in the same way.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement and a method of using a photoresist for forming a photoresist for protecting non-etched portions when the same pattern is formed on the front and back of silicon or glass by etching.

[0002]

2. Description of the Related Art Semiconductor chips and mechanical parts, which are electronic parts manufactured with high processing accuracy by etching and the like, are becoming more and more important. Of the many components, a substrate of an ink jet recording head in which the same pattern is formed on the front and back sides by etching with two kinds of shallow shallow grooves will be described as an example.

Since the actual shape of the groove of the recording head is complicated as described later, the structure and function of the recording head having five nozzles will be described with reference to FIG. (a) is a plan view of a partially broken surface, and (b) is a cross-sectional view of a central flow path. Ink reservoir 32
Further, the substrate 31 provided with the plurality of diaphragms 33, the pressurizing chamber 34, the flow path 35, and the nozzle 36 is bonded to the vibration plate 37 bonded to the piezoelectric element 39 via the conductive film 38. Ink is filled from an ink supply hole (not shown) to the pressure chamber 34 via the ink reservoir 32 so that no bubbles remain, and voltage is applied by means (not shown) to apply a piezoelectric element 39.
Is transformed into the pressurizing chamber 34, and ink is ejected from the nozzle 36 as an ink point by utilizing the fluid resistance of the diaphragm 33 for printing.
It was configured to be able to draw.

In an actual recording head, 24 nozzles are arranged on one side at an interval of 256 μm, and the same number of nozzles are arranged on the back side between the front side nozzles. The nozzle 36 with a width of 50 μm and the channel 35 with a width of 300 μm have a depth of 40 μm, and the width of the pressure chamber 34 is 1.5 mm and the depth is 100 mm.
μm and the depth is two steps. A variety of materials and construction methods for this substrate have been put into practical use. Here, regarding the content of processing a silicon wafer by dry plasma etching, this etching is performed when a high-frequency electric field is applied between electrodes placed in a special gas. It is a process that can irradiate the generated plasma to remove the silicon surface to which the photoresist is not attached.

FIG. 3 is a view in which four component outlines 11b (outer dimensions are 29 × 44 mm) in which fine recesses are omitted are formed on a substrate 11 having a reference end 11a and a diameter of 4 inches. The same pattern has the same back surface. It is also formed on the part. Since the front and back sides are integrally formed as a recording head, the positions of the front and back sides need to be well aligned, and the alignment mark position 12 between the photomask (not shown) and the unprocessed substrate 11 is set at the center of the substrate 11.

FIG. 4 (a) shows the alignment mark on the front surface, the shaded portion is the light-shielding film, and the blank portion is transparent. This shape is hereinafter referred to as the A mark, and (b) is the alignment mark on the back surface. After that, it is called B mark. Edge 1 by overlapping these two
By using 5, the four transparent parts were made equal and the positions were aligned as (c). FIG. 5A is a diagram showing alignment for forming shallow grooves on both surfaces of the substrate 13 coated with photoresist on both surfaces, and a shallow mask 21 having an A mark 21a and a mask pattern (not shown) on the back surface. After aligning the position of the shallow mask 22 having the B-marked mask 22a with FIG. 4, the substrate 13 is inserted and exposed, the photoreceptive portion of the altered photoresist is removed to form a mask, which is then etched by another device. Remove the photoresist on the mask from.

Next, (b) is an exposure diagram in which a deep mask is formed on a substrate 13b with an A mark coated with a photoresist. The deep mask 23 having a B mark 23a on the back surface is positioned by the alignment mark, and A mask is formed on the substrate and etched, and then the photoresist is removed. (c) is an exposure diagram in which a deep mask is formed on a substrate 13c with a B mark coated with a photoresist, and the deep mask 24 having an A mark 24a on the back surface is positioned by the alignment mark and similarly processed.

[0008]

In the example described in the prior art, the front and back surfaces are the same, and when the front and back surfaces are seen through, a line-symmetrical pattern is formed, and there are four types of etching photomasks for parts having two kinds of shallow grooves on both sides. Met. Therefore, it is necessary to prepare four kinds of photomask original plates, and it is necessary to prepare four kinds of expensive photomasks, and it is necessary to take care when using them. An object of the present invention is to provide a photomask that reduces the number of types and a method of using the photomask.

[0009]

SUMMARY OF THE INVENTION According to the present invention, when a same pattern having two different depths is etched on the front and back surfaces of a substrate, the photoresist on the substrate forms a protective mask to be a non-etched portion. The two photomasks for use are provided with two kinds of alignment marks different from each other at two points of line symmetry from the center line of line symmetry when the front and back patterns of the substrate are seen through.

Further, according to the present invention, two kinds of mask patterns for depth are separately provided on two photomasks for forming a photoresist for etching the same pattern having two kinds of depths on the front and back surfaces of the substrate, and the front and back surfaces of the substrate are separately formed. When forming a see-through pattern, two different alignment marks are formed at two points of line symmetry from the center line of line symmetry, and the two masks for shallow etching are turned over to align the different alignment marks. The substrate with the photoresist attached between the two photoresist masks is placed and exposed, and the exposed photoresist is removed before etching, and the exposure is performed by aligning different alignment marks of this substrate with the photoresist attachment and the deep etching mask,
This is a method of use in which etching is performed after removing the exposed photoresist.

[0011]

According to the present invention, the two kinds of alignment marks of the photomask are set at two positions apart from each other by line symmetry by utilizing the line symmetry when the front and back patterns of the substrate are seen through. Since it is possible to position one piece by turning over one piece and aligning the transparent part of the mask's match mark, it is only necessary to set one kind.For a deep digging photomask, the match mark is provided in the same place in reverse, and the etching finished product after shallow digging Since the alignment mark can be positioned on the transparent portion of the mask, only one type is required.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention is shown in FIG. 1, in which (a) is an explanatory view of double-sided exposure, and shows a line symmetry of a shallow mask 1 having line symmetry when seeing through the front and back of a substrate and having a pattern not shown. An A mark 1a and a B mark 1b are provided at the positions. When the same product is turned over and facing each other, A mark 1m and B mark 1 on the back side
n is a matching mark with the B mark 1b and the A mark 1a of the mask 1 below. In this matched state, the silicon substrate 13 with the photoresist is put therein, and thereafter, the processing is performed according to the conventional technique. (b) is a diagram in which the mark of the deep mask 2 is aligned on the surface of the substrate 13a with the photoresist manufactured and etched in (a). A mark 2m and B mark are formed on the substrate 13a mark.
Align marks 2n. The figure in which the deep mask 2 is marked on the back surface of the photoresist-coated substrate 13a manufactured in (a) is the same as (b).

Although two types of masks having a shallow depth are explained here, if more types are required, the first alignment mark is set to 4
The photomasks may be provided in more than one place, and the second and subsequent photomasks may be used in each of the two places.

[0014]

According to the present invention, it is possible to reduce the number of types of photomasks capable of groove-forming a substrate into two types for depth and shallowness by dry plasma etching to half the conventional type. Further, since only one type of photomask is handled at the time of exposure for deep and shallow etching, the work is easy, and since the photomask is not replaced, the work time can be shortened and the alignment marks are separated. Therefore, the positioning becomes extremely good, and it is possible to provide an inexpensive product with good positioning accuracy.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of the present invention, (a) is an explanatory view of double-sided exposure, and (b) is an explanatory view of deep mask exposure.

2A and 2B are explanatory views of an ink jet recording head according to the present invention, in which FIG. 2A is a plan view of a part of a cross section, and FIG. 2B is a cross sectional view of a flow path in a central portion of FIG.

FIG. 3 is a schematic plan view of a processing target according to the present invention.

FIG. 4 is an enlarged view of a conventional alignment mark, (a) is a plan view of an A mark of a shallow mask, (b) is a plan view of a B mark,
(c) is a plan view with the AB mark

FIG. 5 is a perspective view of conventional exposure, (a) is an explanatory diagram of double-sided exposure, (b) is an exposure diagram of a B mark surface of a deep mask, and (c) is an exposure of an A mark surface of a deep mask. Figure

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 shallow mask 1a A mark 1m A mark (rear surface) 2 deep mask 2n B mark (rear surface) 13 substrate 21 shallow mask 23 deep mask 34 pressure chamber 36 nozzle

Claims (2)

[Claims] 1. A photomask for forming a protective mask, which is a non-etched portion, from a photoresist on a substrate when two patterns having the same depth are etched on the front and back surfaces of the substrate. A photomask for etching, characterized in that two kinds of alignment marks different from each other are provided at two points of line symmetry from the line center of the line symmetry when seeing through the front and back patterns of the substrate. 2. Two kinds of mask patterns for depth are separately provided on two photomasks for forming a photoresist for etching the same pattern having two kinds of depths on the front and back of the substrate, and the patterns on the front and back of the substrate are seen through. Two different alignment marks are formed at two points of line symmetry from the center line of line symmetry, and one of the two masks for shallow etching is turned over and the two different alignment marks are aligned. The substrate with the photoresist attached is placed between the photomasks and exposed, and the exposed photoresist is removed before etching.This substrate with the photoresist attached and the alignment marks on the deep etching mask are also exposed and exposed. A method of using a photomask for etching, which comprises etching after removing the photoresist.