JPH0996909A - Resist pattern of t-shaped section and its production as well as magneto-resistive thin-film element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide resist patterns having T-shaped sections of a good contrast in order to lower the defective article rate at the time of forming the electrode patterns, etc., of a magneto-resistive thin-film element. SOLUTION: The homogeneous resist patterns are formed by using a positive type resist for image reversal and the sections 110 thereof have the T-shape. The min. angle formed by the tangent at the bottom edge 116 of the cross bar part and a substrate surface 122 is defined as α and the spacing between the lower edge 116 in the cross bar part and the substrate surface at the intermediate of the intersected point Wo of the perpendicular down from the outermost edge 118 of the cross bar apart and the substrate surface and the contact point Wi of the side edge 112 of a vertical bar part and the substrate surface is defined as h, then α and h in an h-αgraph exist in the quadrilateral passing A:α=0 deg., h=0.01μm, B:α=20 deg., h=0.01μm, C:α=20 deg., h=0.2μm, D:α=0 deg., h=0.3μm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resist pattern having a T-shaped cross section, a method for manufacturing the same, and at least one of a magnetoresistive effect film, an electrode film for a magnetoresistive effect film, and a shield film.
A magnetoresistive effect thin film element in which a layer is formed by using the resist pattern.

[0002]

2. Description of the Related Art Conventionally, the following method is known as a method for forming a resist pattern having an inverted trapezoidal or T-shaped cross section.

(A) Method of forming a pattern having an inverted trapezoidal cross section and composed of a single resist (a) Method of using a single layer negative resist (i) UV exposure of a negative resist A method of performing exposure and patterning by an ordinary method except that the exposure amount is made low (see JP-A-61-136226).

(B) Method of using one layer of positive type resist (i) Method of making the substrate side of the resist have a lower temperature than the surface side during pre-baking and post-baking. Pre-baking is described in JP-A-54-72678, and post-baking is described in JP-A-3-101218. (Ii) A method of exposing a positive type electron beam resist film with deep ultraviolet rays (see JP-A-1-50423). (iii) A method of applying a novolac type resist and holding it in a high vacuum before exposure (see Japanese Patent Laid-Open No. 3-257817). (Iv) A method of exposing the resist coated on the transparent substrate to ultraviolet rays from both the front and back sides (see JP-A-5-37275). (V) When exposing the positive resist with an electron beam,
A method in which a patterned portion and a non-patterned portion are once formed, a protective film is formed on them, and the non-patterned portion is removed by using this protective film to shorten the exposure time (JP-A-51-
147261). (Vi) A method in which the ultraviolet absorption coefficient of the resist polymer itself or the amount of a crosslinking agent added to the resist is set to a predetermined value (see JP-A-58-16527). (vii) A method in which a photoresist colored with a dye that absorbs exposure light is applied onto a substrate and then immersed in a solvent to control the color density distribution in the thickness direction of the resist (JP-A 1-2).
(See Japanese Patent No. 84851).

(C) Method of using a positive type resist (1 layer) having an image reversing function (i) Method of using AZ5200E series manufactured by Hoechst Co. as a resist By using this resist, an inverted trapezoidal cross section is obtained. It is known that patterns can be created {AZ
5200E series catalog, M.P. Bolsen, "Submicron Processing Technology by Image Reversal of Positive Photoresist," Electronic Materials, 6, 1 (1986), and M. Spac.
et al, "Mechanism and lithographic evaluation of im
age reversal in AZ5214 scattering. ", Proc.of confe
rence on photopolymers principle processing and ma
terials., Ellenville (1985)}. In this resist, an image reversal function is imparted by adding a negative working agent such as a basic amine to a positive resist which is a mixture of an alkali-soluble phenol resin and naphthoquinonediazide.

(B) Method of forming a T-shaped cross section (a) Method of using a single-layer resist (i) Method of exposing a negative resist using two kinds of charged beams having different ranges (special (See Japanese Laid-Open Patent Publication No. 62-105423). However, in the publication, the pattern having a T-shaped cross section is changed to a pattern having a rectangular cross section due to contraction after rinsing and drying.

(B) Method of using two-layer resist (i) Exposure to a two-layer structure positive resist with a predetermined irradiation amount corresponding to a predetermined pattern shape and exposure to a central portion of the same pattern shape with a predetermined irradiation amount And a method of performing double exposure with an appropriate irradiation amount (see JP-A-62-141548). (Ii) A method of simultaneously exposing a predetermined pattern to electron beam resists of upper and lower two layers laminated via a separation layer (see Japanese Patent Publication No. 63-55208). (iii) A method of forming a metamorphic layer having resistance to the development processing of the second photoresist film on the surface of the first photoresist film (see Japanese Patent Laid-Open No. 2-65139). (Iv) A method in which a resist film having a two-layer structure is provided and the pattern opening width on the upper surface of the lower resist layer is made larger than the opening width on the lower surface of the upper resist layer (see Japanese Patent Laid-Open No. 2-208934).

Although various conventional examples have been described above, most of them require the use of two layers of resist even when the resist pattern has an inverted trapezoidal cross-sectional shape and is recognized as a T-shaped cross-section. Since it has been necessary to perform the exposure twice, it is very difficult to form and it is not realistic.

By the way, as a method for forming an electrode pattern or the like on a substrate, there are a lift-off method, a milling patterning method and a combination method thereof. The outline of these methods and the reason why a resist shape having a T-shaped cross section is desirable will be described below.

Milling patterning method An example of a pattern forming method using ion milling is shown in FIG. In this method, first, a milled film is formed on the entire surface of the substrate. Next, a resist layer is formed on the surface of the film to be milled and patterned to form a resist cover, and the film to be milled is ion milled using the resist cover as a mask. After that, the resist cover is removed by dissolution with an organic solvent or ashing to obtain a patterned film to be milled.

When the resist cover has a rectangular cross section or an inverted trapezoidal shape as in the conventional example, when the film to be milled is etched by the ion milling method, particles scattered from the film to be milled adhere to the side wall of the resist cover. May grow to reach the surface of the film to be milled, that is, to reattach to the film to be milled (see FIG. 3). Therefore, when the resist cover is removed, the redeposited portion may remain as a fine protrusion on the surface of the milled film.

Even if the resist cover has a T-shaped cross section, particles scattered from the film to be milled adhere to the resist cover during etching. In the case of the T-shaped resist cover, however, the lower part of the resist cover is constricted, resulting in a constriction. If the height of the portion is sufficient, the adhesion layer does not grow to be continuous with the surface of the film to be milled (see FIG. 4). For this reason, when the resist cover is removed, the adhesion layer is also removed together with the resist cover, and a milled film to be milled can be obtained in which the redeposited portion does not remain on the surface of the film to be milled.

Lift-Off Method Next, the lift-off method will be described. Here, a case where a film patterned by the lift-off method is formed on the above-mentioned patterned film to be milled will be described. This method is used, for example, in a series of steps of forming a lead layer on the magnetoresistive effect film.

An example of this lift-off method is shown in FIG. In the method shown in FIG. 5, first, a substrate having a patterned film to be milled on its surface is prepared, a resist layer is formed on the substrate, and then patterned to form a resist cover as shown. Next, a patterning film such as metal or ceramics is formed on the entire surface of the substrate including the resist cover. Next, in an organic solvent capable of dissolving the resist, a region of the film to be patterned which is present on the resist cover is removed together with the resist cover to obtain a patterning film.

In this process, the organic solvent must penetrate well into the resist cover. However, when the resist cover has an inverted trapezoidal cross-sectional shape as in the conventional example, when the patterning film is formed, the patterning film adheres to the side wall of the resist cover as shown in FIG. I will cover it. For this reason, the organic solvent may not sufficiently penetrate into the resist cover, and the resist cover may not be removed.

On the other hand, when the resist cover has a T-shaped cross section, as shown in FIG. 7, if the height of the constricted portion (below the eaves portion) under the resist cover is less than the thickness of the patterning film. For example, when the patterning film is formed, it is formed on the upper surface and the side wall of the resist cover eaves portion, but since the constricted portion is behind the eaves portion, it is not formed on the constricted portion. Therefore, the formed film does not completely cover the resist cover, the organic solvent permeates into the resist cover from the constricted portion, and the film formed thereon together with the resist cover can be reliably removed. .

Between the milling patterning method and the lift-off method
Combination Method An example of this combination method is shown in FIG. In this method, first,
After forming a film to be milled on the entire surface of the substrate, a resist layer is formed, and the resist layer is patterned to form a resist cover. In the illustrated example, a resist cover having an inverted trapezoidal cross section is formed. Next, after patterning the film to be milled by the ion milling method, without removing the resist cover, the resist cover is used as it is as a resist cover of the lift-off method to form a metal, ceramics or the like. Next, the resist cover is dissolved with an organic solvent to remove the film of metal, ceramics, or the like existing on the resist cover together with the resist cover. By such a process, a continuous film of the film to be milled patterned by the ion milling method and the film of metal or ceramics patterned by the lift-off method is formed on the surface of the substrate.

In this combined use method, when the resist cover has a rectangular cross section or an inverted trapezoidal shape as in the conventional example,
For the reasons described above, minute protrusions may remain at the boundary between the film patterned by the ion milling method of the continuous film and the film patterned by the lift-off method. In some cases, the resist cover cannot be removed.

When the resist cover has a T-shaped cross section,
Due to the reason mentioned above, the above problem does not occur,
A good continuous film of the film patterned by the ion milling method and the film patterned by the lift-off method can be obtained.

[0020]

According to the prior art, although a resist pattern having an inverted trapezoidal cross section can be obtained by a single-layer resist, when a resist pattern having a T-shaped cross section is to be formed, a T-shaped resist having a good contrast is obtained. No cross section was obtained. For example, in the case of a one-layer resist, FIGS.
As shown in (3), only a resist pattern having an inverted trapezoidal cross section was obtained (all from the AZ5200E catalog). FIG. 17 shows an excimer laser, FIG. 18 shows an i-line, FIG. 19 shows a g-line, and FIG. 20 shows a broadband light including the i-line, the g-line and the h-line. The cross section is not T-shaped regardless of which exposure light is used.

On the other hand, when the conventional technique is used to form a resist pattern having a T-shaped cross section with a two-layer resist, it takes a lot of work and mixing between resists occurs at the resist interface, which is excellent. No T-shape with contrast was obtained.

As described above, a resist pattern having a T-shaped cross section with good contrast has not been obtained in the related art. Therefore, the conventional resist pattern having the T-shaped cross section is used to obtain the magnetoresistive effect of the magnetoresistive thin film element. When the effect film electrode pattern or the like is formed, the electrode material often remains in a portion other than the necessary electrode pattern, resulting in a high defective product rate.

An object of the present invention is to provide a resist pattern having a T-shaped cross section with good contrast in order to suppress the defective product rate when forming an electrode pattern or the like of a magnetoresistive thin film element to be extremely low. It is also to provide a magnetoresistive effect thin film element in which an electrode pattern or the like is formed using this resist pattern.

[0024]

Such an object is achieved by any of the following constitutions (1) to (14). (1) Substantially uniform resist pattern formed by using a resist agent having a negative working agent added to a positive resist containing a mixture of an alkali-soluble phenol resin and naphthoquinonediazide to give an image reversal function And a vertical bar portion whose cross-sectional shape extends upward from the substrate surface to form a substantially T-shaped vertical bar portion, and a horizontal bar which is continuous with the vertical bar portion and is spaced from the substrate surface. A T-shape having a horizontal bar portion extending substantially to form a T-shaped horizontal bar portion, and in the cross-sectional shape, the minimum value of the angles formed by the tangent line of the lower edge of the horizontal bar portion and the substrate surface is α. And a horizontal bar portion at an intermediate position between an intersection point Wo of a perpendicular line drawn from the outermost edge of the horizontal bar portion to the substrate surface and the substrate surface, and a point Wi at which the side edge of the vertical bar portion on the outermost edge side contacts the substrate surface. In the h-α graph, α and h are A: α = 0 °, h = 0.01 μm, B: α = 20 °, h = 0.01 μm, C, where h is the distance between the lower edge and the substrate surface. : Α = 20 °, h = 0.2 μm, D: α = 0 °, h = 0.3 μm existing within a range surrounded by a quadrilateral that connects four points in this order (including the sides) Resist pattern with T-shaped cross section. (2) In the h-α graph, α and h are A: α = 0 °, h = 0.01 μm, X: α = 5 °, h = 0.01 μm, Y: α = 5 °, h = 0. 15 μm, Z: α = 0 °, h = 0.15 μm A resist having the T-shaped cross section of the above (1) existing within a range surrounded by a quadrangle (including the sides) connected in this order. pattern. (3) In the h-α graph, α and h are A: α = 0 °, h = 0.01 μm, X: α = 5 °, h = 0.01 μm, G: α = 5 °, h = 0. 1 μm, H: α = 0 °, h = 0.1 μm A resist having the T-shaped cross section of the above (1) existing within a range surrounded by a quadrangle (inclusive of the sides) connected in this order. pattern. (4) The distance W between the intersection point Wo of the perpendicular line drawn from the outermost edge of the horizontal bar portion to the substrate surface and the substrate surface, and the point Wi at which the side edge of the vertical bar portion on the outermost edge side contacts the substrate surface is W. At this time, the resist pattern having a T-shaped cross section according to any one of (1) to (3) above, wherein W = 0.03 to 3 μm. (5) The resist pattern having a T-shaped cross section according to any one of (1) to (4) above, wherein Hw = 0.1 to 7 μm, where Hw is the maximum width of the horizontal bar portion. (6) When the width of the region where the vertical bar portion is in contact with the substrate surface is Vw, the resist pattern having the T-shaped cross section of (5) above is: Vw / Hw = 0.1 to 0.995. (7) The surface is formed on the surface of a substrate composed of a metal material or a ceramic material. (1)
A resist pattern having a T-shaped cross section according to any one of to (6). (8) Formation of a resist coating film, exposure, and reversal baking using a resist agent in which a negative working agent is added to a positive resist containing a mixture of an alkali-soluble phenol resin and naphthoquinonediazide to give an image reversal function. When a resist pattern is manufactured by a patterning process having steps of development and development in this order, under the condition that a resist pattern having an inverted trapezoidal cross section can be obtained, the thickness of the resist coating film is reduced, the exposure amount is reduced, and the reversal is performed. By adding at least one kind of condition change selected from a lower bake temperature, a shorter reversal bake time, a higher developer temperature and a longer development time,
A method of manufacturing a resist pattern having a T-shaped cross section, which enables manufacturing of a resist pattern having a T-shaped cross section. (9) When the focus position at the time of exposing the resist coating film is displayed with the direction approaching the substrate as the minus with respect to the resist coating surface as the reference and the direction away from the substrate as the plus,
The T of the above (8), wherein the focal position is -1 to +10 μm.
A method of manufacturing a resist pattern having a shaped cross section. (10) The method for producing a resist pattern having a T-shaped cross section according to (8) or (9), wherein the reversal bake is performed at a temperature of 100 to 123 ° C. for 30 seconds to 13 minutes. (11) The method for producing a resist pattern having a T-shaped cross section according to any one of (8) to (10), which is for producing a resist pattern having a T-shaped cross section according to any one of (1) to (7). (12) At least one layer of a magnetoresistive effect film and an electrode film for a magnetoresistive effect film is formed by a lift-off method using the resist pattern having the T-shaped cross section of any one of (1) to (7) above as a resist cover. A magnetoresistive thin film element that has been manufactured. (13) At least one of a magnetoresistive effect film, an electrode film for a magnetoresistive effect film, and a shield film is formed by a milling patterning method using the resist pattern having the T-shaped cross section of any one of (1) to (7) above as a resist cover. A magnetoresistive effect thin film element in which a layer is formed. (14) A magnetoresistive effect film and an electrode for a magnetoresistive effect film by using the resist pattern having the T-shaped cross section of any one of the above (1) to (7) as a resist cover by a combined method of a milling patterning method and a lift-off method. A magnetoresistive effect thin film element in which a continuous film with a film is formed.

[0025]

In the present invention, the resist pattern having the T-shaped cross section is realized by using the one-layer resist, that is, the resist which is wholly homogeneous, and controlling the patterning conditions as described above.

The T-shaped cross-section resist pattern of the present invention is
When an electrode pattern of a magnetoresistive thin film element is formed using this because it is formed of a uniform resist and has a high-contrast T-shaped cross-section with α and h within a predetermined range. The defective product ratio can be remarkably reduced, and in the best case, a good product ratio of 100% can be realized.

The basic application of the present application (Japanese Patent Application No. 7-20
9950), one layer of resist is used and
There is no example in which a T-shaped cross-section pattern can be formed by a single image exposure, but the document “IE” published after the application for the basic application of the present application is made.
EE TRANSACTIONS ON MAGNETICS, VOL.32 NO.1, JANUARY 1
Pp. 25 to 30 of "996", a resist pattern having a T-shaped cross section is described. In the same document, the exposure amount and the post-exposure bake (corresponding to the reversal bake in this specification)
The influence of the change in temperature on the cross-sectional shape and the amount of redeposited material remaining after lift-off was measured, and the results are shown in Table 3. However, this document does not describe the absolute value of the exposure amount or the bake temperature, nor the type of resist used. The resist pattern described in Table 3 of the same document is formed by using i-line cut broadband light as the exposure light, and the total width (W) of the cross section is 3.6 μm or more. The height (H) of the portion is 0.2 μm or more. The type of exposure light was determined from the exposure device used in the same document.

In this document, a Si wafer is used as the substrate. Further, FIG. 4 of the same document shows a scanning electron microscope photograph of a cross section of the substrate and the resist pattern. As far as FIG. 4 is seen, the resist pattern is S.
It appears to be formed directly on the i-wafer surface. However, according to the experiments by the present inventors, it was impossible to directly form a resist pattern having a T-shaped cross section on the surface of the Si wafer. Specifically, the resist used in the present invention has poor adhesion to the Si wafer, the resist pattern of the T-shaped cross section has a small contact area with the substrate, and in the present invention, it is preferable to use i-line for fine patterning. Since a different resist pattern is produced, it is considered that the resist pattern is easily peeled off from the Si wafer. Therefore, in the present invention, the patterning condition is controlled as described above, and S
By using a substrate having a surface other than i or SiO ₂ , it is possible to form a fine T-shaped sectional resist pattern. On the other hand, the above document does not describe a fine T-shaped sectional resist pattern using i-line.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below.

The resist pattern of the present invention is formed by patterning a positive resist compatible with image inversion by a method described later, and is a uniform pattern because it is a pattern of a single layer resist.

In the present specification, the image-reversal-compatible positive resist is a resist agent containing a positive resist as a main component and a negative working agent added thereto to impart an image reversal function. Image exposure → heating { Hereinafter, reversal bake (RB)} → uniform exposure (hereinafter, flood exposure)
→ When patterning is carried out by a series of steps of development, the image-exposed portion remains like the negative resist.

In the present invention, a positive resist containing a mixture of an alkali-soluble phenol resin and naphthoquinonediazide as a main component, and a negative working agent added thereto is used as an image inversion-compatible positive resist.

The above alkali-soluble phenol resin is
Examples thereof include phenol formaldehyde novolac resin and cresol formaldehyde novolac resin.

The above-mentioned naphthoquinonediazide compound is a compound having at least one naphthoquinonediazide group, which increases the solubility in an alkaline solution by irradiation with active light. As such compounds, compounds having various structures are known, and one of hydroxyl compounds and an ester of o-benzo or o-naphthoquinonediazide sulfonic acid are particularly preferable. These compounds include 2,2'-dihydroxy-diphenyl-bis- [naphthoquinone-1,2-diazide-5-sulfonate], 2,2'4,4'-tetrahydroxydiphenyl-tetra [naphthoquinone- 1,2-diazide-5-sulfonic acid ester], 2,3,4-trioxybenzophenone-bis- [naphthoquinone-1,2-diazide-5-
Sulfonic acid ester], etc.
Examples thereof include polyhydroxyphenyl obtained by polycondensation of acetone and pyrogallol and esters of naphthoquinone-1,2-diazide-5-sulfonic acid described in Japanese Patent No. 403.

As the above-mentioned negative working agent,
Examples thereof include amines, aromatic hydrocarbons having a hydroxyl group, 1-hydroxyethyl-2-alkylimidazoline, and shellac.

Examples of the amine of the negative working agent include dialkylamine, trialkylamine, secondary amine or tertiary amine having a hydroxyalkyl group (hereinafter referred to as hydroxyalkylamine), dialkylamino aromatic hydrocarbon, A cyclic polyamine can be mentioned. Specific examples of the dialkylamine include diamylamine, diheptylamine and didecylamine, and specific examples of the trialkylamine include tributylamine, triamylamine, trihexylamine and triisoamylamine, and specific examples of the hydroxyalkylamine. Is diethanolamine, N-methylethanolamine, N-methyldiethanolamine, dipropanolamine, triethanolamine,
Specific examples of the dialkylamino aromatic hydrocarbon include diethylaniline and dipropylaniline, and specific examples of the cyclic polyamine include hexamethylenetetramine.

As the aromatic hydrocarbon having a hydroxyl group, a hydroxyl group which can be esterified or etherified is 1
Aromatic hydrocarbons having two or more can be used. Examples of the aromatic hydrocarbon having a hydroxyl group include a resin having a benzene ring having a hydroxyl group and a hydroxybenzene compound, and specific examples of the resin having a benzene ring having a hydroxyl group include phenol formaldehyde novolac resin and cresol formaldehyde novolak resin. Can be raised. Specific examples of the hydroxybenzene compound include pyrogallol, phloroglucinol,
2,2-bis (4-hydroxyphenyl) propane,
Specific examples of the 1-hydroxyethyl-2-alkylimidazoline include compounds having an alkyl group having 7 to 17 carbon atoms and mixtures thereof.

Preferred compounds as these negative working agents are, for example, triethanolamine and N-.
There are methylethanolamine, N-methyldienolamine, diethylaniline, hexamethylenetetramine, tributylamine, triisoamylamine, metacresol formaldehyde resin, shellac, 1-hydroxyethyl-2-alkylimidazoline and the like.

The amount of the negative working agent used is preferably in the range of about 0.005 part by weight to about 1 part by weight, more preferably about 0. 01 parts by weight to about 0.3
Parts by weight, preferably in the range of about 0.005 parts by weight to about 10 parts by weight, more preferably in the range of about 0.01 parts by weight to about 3 parts by weight in the case of an aromatic hydrocarbon having a hydroxyl group or shellac. , 1-hydroxylethyl-2-
In the case of alkyl imidazolines preferably about 0.00
It is in the range of 5 to about 0.1 parts by weight, more preferably in the range of about 0.01 to about 0.07 parts by weight.

In addition to the above components, various additives can be added to the photosensitive resin composition used in the present invention. For example, to increase image strength or as a binder,
Resins that can be mixed homogeneously with the above components, for example styrene-
It is also possible to add a maleic anhydride copolymer, a styrene-acrylic acid copolymer, a methacrylic acid-methyl methacrylate copolymer and the like.

The detailed composition of this type of resist is described in JP-B-55-32088 and British Patent 844.
No. 039, US Pat. No. 4,104,070, and the like.

As shown in FIG. 1, the cross-sectional shape 110 of the resist pattern of the present invention has a vertical bar portion 112 extending upward from the surface 122 of the substrate 120 and forming a substantially T-shaped vertical bar portion, and this vertical bar portion 112. And a horizontal bar portion 114 which is continuous with the bar portion and extends laterally in a state of being spaced apart from the substrate surface to form a substantially T-shaped horizontal bar portion 114.

In the sectional shape shown in FIG. 1, the minimum value of the angles formed by the tangent line of the lower edge 116 of the horizontal bar portion and the substrate surface 122 is α, and the perpendicular line drawn from the outermost edge 118 of the horizontal bar portion to the substrate surface. And the substrate surface 122 intersect with the point Wo (the distance between Wo and Wi is W) between the point W where the side edge of the vertical bar portion 112 on the outermost edge 118 side contacts the substrate surface 122 (from Wo). When the distance between the lower edge 116 of the horizontal bar portion and the substrate surface 122 at a distance W / 2) is h, α and h are A: α = 0 °, h as shown in the h-α graph of FIG. = 0.01 μm, B: α = 20 °, h = 0.01 μm, C: α = 20 °, h = 0.2 μm, D: α = 0 °, h = 0.3 μm, connected in this order. It exists within the range surrounded by the quadrangle (including the side), and preferably A: α = 0 °, h = 0. .01 μm, X: α = 5 °, h = 0.01 μm, Y: α = 5 °, h = 0.15 μm, Z: α = 0 °, h = 0.15 μm, connected in this order. It exists within the range surrounded by the quadrangle (including on the side), and more preferably A: α = 0 °, h = 0.01 μm, X: α = 5 °, h = 0.01 μm, G: α = 5 °, h = 0.1 μm, H: α = 0 °, h = 0.1 μm, which exists within a range (including on the side) surrounded by a quadrangle connected in this order. By setting α and h in such a range in the T-shaped cross-section resist pattern, good lift-off and ion milling can be performed for the first time, and the defective product rate becomes less than 20%. Conventionally, there is no pattern having such a T-shape with a single resist. Note that α = 0 ° means the lower edge 1 of the horizontal bar portion.
This means that the tangent line at 16 and the substrate surface 122 are parallel.

In FIG. 1, the distance W between the point Wo and the point Wi
Is preferably W = 0.03-3 μm, more preferably W = 0.1-3 μm, still more preferably W = 0.2-1.
μm. By setting W in such a range, the defective product rate further decreases.

In FIG. 1, where T is the height of the resist pattern, preferably T = 0.3 to 3 μm, more preferably T = 0.4 to 2 μm, and further preferably T =.
It is 0.4-1 μm. If T is too large or too small, it becomes difficult to form a T-shaped cross section. If T is too small, it cannot be used as a resist cover. In addition, when a pattern having too large T is used as a resist cover during milling, the end surface of the milling pattern lays down, that is, it becomes parallel to the substrate surface, which is not preferable.

In FIG. 1, an angle between a half line which is in contact with the side edge of the vertical bar portion and extends above the substrate at a point Wi and a half line which extends from the point Wi in parallel with the substrate surface toward the inside of the vertical bar portion is β. At this time, β is preferably 10 to 160 °, and more preferably β is 70 to 110 °.

In FIG. 1, a half line extending from the substrate surface and in contact with the side edge of the horizontal bar portion at a height of T / 3 from the substrate surface, and a vertical bar portion parallel to the substrate surface from the intersection of the half line and the substrate surface. When the angle formed by the half line extending in the direction away from is γ, preferably γ = 20 to 120 °,
More preferably, γ = 60 to 100 °, and even more preferably γ = 80 to 90 °.

In FIG. 1, the maximum width of the horizontal bar portion is Hw.
, Hw = 0.1 to 7 μm, and more preferably Hw = 0.3 to 3 μm.

In FIG. 1, when the width of the region where the vertical bar portion is in contact with the substrate surface is Vw, preferably Vw /
Hw = 0.1 to 0.995, more preferably Vw / Hw
= 0.15 to 0.95.

The upper surface of the resist pattern having a T-shaped cross section according to the present invention usually has a concave surface, but may have a flat surface or a convex surface when Hw is small.

In the present specification, the substrate surface is the surface where the vertical bar portions of the resist pattern are in contact,
For example, when a resist pattern is formed on the surface of the milled film or the like, the surface of the milled film or the like is the substrate surface.

The material of the substrate surface on which the T-shaped resist pattern of the present invention is formed is preferably a metal (including alloy) material or a ceramic material. Of the metallic materials, simple metals include Cr, Al, W, Te, and M.
o, Fe, Ni, Co, Mn, Ti, Ta, Au, A
g, Cu, etc. can be preferably used. As the alloy, Fe-Ni, Ni-Mn, Fe-Ni-Co, Fe
-Co etc. can be used preferably. As the ceramic material, oxides such as NiO, Al ₂ O ₃ and ZrO ₂ , oxides such as LiNbO ₂ , LiTaO ₃ and ferrite, and carbides such as AlTiC can be preferably used. The crystallinity of these is not particularly limited.

By using a substrate having a surface made of such a material, a resist pattern having a sectional shape characteristic of the present invention can be formed. In the present invention, the Si single crystal substrate that is often used in the manufacture of semiconductor devices is not used. According to an experiment conducted by the inventor of the present invention, Si
Even if the above resist agent is used, a resist pattern having a cross-sectional shape that is characteristic of the present invention cannot be formed on a single crystal substrate. Also, a substrate whose surface is made of silicon oxide such as SiO ₂ cannot form the resist pattern as described above like the Si substrate, and is not used in the present invention.

Next, a method of forming a resist pattern having a T-shaped cross section according to the present invention will be described.

FIG. 10 shows the patterning process of the positive resist corresponding to the image inversion, and FIG. 11 shows an example of the chemical reaction that occurs in the resist at each stage, and this patterning process will be described for each stage (details thereof will be described. , M. Spac e
t al, "Mechanism and lithographic evaluation of ima
ge reversal in AZ5214 diffuse. ", Proc.of confer
ence on photopolymers principle processing and mat
erials., Ellenville (1985)). In addition,
The following description is for an example using a basic amine as a negative working agent.

(1) First stage exposure: An image reversal-compatible positive resist 2 is applied to the upper surface of the substrate 1, prebaked, and then ultraviolet rays A (wavelength: 300 to 300) are applied through a mask 3 having a predetermined pattern on the upper surface of the resist film. Fifty
0 nm) is irradiated (exposed). In the exposed portion 4 of the resist 2, diazonaphthoquinone undergoes Wolff transition to become indenecarboxylic acid (see Formula 1 in FIG. 11). The indene carboxylic acid becomes an amine salt of carboxylic acid which is somewhat unstable by an acid-alkali reaction with a basic amine which is a negative working agent (see Formula 2 in FIG. 11).

(2) Second stage reversal bake (R
B) After the reaction of Equation 2, the resist is reversal baked. The temperature of the reversal bake is preferably 90 to 130 ° C. Upon heating with a reversal bake, the amine salt of the carboxylic acid rapidly undergoes a decarbonylation reaction to become indene insoluble in the alkaline aqueous solution (see Formula 3 in FIG. 11). Indene is not only insoluble in an alkaline aqueous solution, but also inactive to subsequent irradiation with ultraviolet rays and heating. The reversal bake in this case corresponds to the post-baking in the normal process, and the post-baking may not be performed in this process.

(3) Third Stage Flood Exposure Here, the resist was irradiated with ultraviolet rays B, and diazonaphthoquinone, which was the photosensitive group of the unexposed portion 5 which was unexposed at the time of the first exposure, was indene soluble in an alkaline aqueous solution. It becomes a carboxylic acid (see formula 1) and subsequently becomes a amine salt of a carboxylic acid by reaction with a basic amine (see formula 2). This amine salt of carboxylic acid is also soluble in an alkaline aqueous solution. The wavelength of the ultraviolet ray B may be the same as that of the ultraviolet ray A, but the wavelength of the ultraviolet ray B is not particularly limited because it is not related to pattern formation. Flood exposure is not always necessary, but when it is not used, a relatively high concentration developer needs to be used, and scum may occur during development.

(4) Fourth Stage Development Finally, by developing with an alkaline aqueous solution, the unexposed area 5 is dissolved and only the exposed area 4 remains, and the patterning is completed.

Among the positive resists compatible with image inversion, commercially available resists are the resist AZ5200E series manufactured by Hoechst. For detailed characteristics of this resist, see M. Bolsen, "Submicron Processing Technology by Image Reversal of Positive Photoresist," Electronic Materials, 6, 1 (1986).

Next, FIG. 12 shows the influence of the conditions of each step on the cross-sectional shape of the resist when the other conditions in the patterning process of the positive resist corresponding to the above-mentioned image reversal are the same. Explained.

(1) Substrate surface The relationship between these patterning conditions and the cross-sectional shape of the resist obtained is as follows: the material of the substrate surface and the substrate surface treatment (HMDS).
It does not depend on the presence or absence of gas phase treatment). Preferably, the surface treatment of the substrate should not be performed.

(2) Resist coating thickness, pre-bake temperature, time As the resist coating thickness is made thinner, a constriction (slit) is formed in the grounded portion of the inverted trapezoidal substrate, and the width of the constriction becomes wider. The cross section changes from an inverted trapezoid to a T-shape. Preferably, the coating thickness of the resist is 3 μm (after prebaking)
The following is good. The lower limit of the coating thickness of the resist is usually 0.3.
It is preferably about 0.5 μm. The pre-bake temperature and the time thereof have almost no effect on the cross-sectional shape of the resist, but the pre-bake temperature is preferably set to the reversal bake temperature or lower.

(3) Exposure amount As the exposure amount is reduced, a constriction (slit) is formed in the grounded portion of the inverted trapezoidal substrate, and the cross section changes from the inverted trapezoidal shape to the T-shaped. The preferred exposure amount varies depending on the type of exposure machine, the wavelength distribution of exposure light {including ultraviolet rays, laser light (excimer, etc.), X-rays, electron beams, etc.}, but in the experiments leading to the present invention, 10-500 mJ / cm ² was preferred. More specifically, the exposure light is i-ray (wavelength 3
When using a 65 nm) cut broadband light or g-line (wavelength 436 nm), and preferably 100 to 500 mJ / cm ^2, more preferably 100 to 400 mJ / cm ^2, more preferably a 100~330mJ / cm ^2, i line Is preferably 10 to 100 mJ / cm ² , more preferably 30 to 60 mJ / cm ² . In order to make the MR film pattern fine in the magnetoresistive (MR) thin film element, it is preferable to use light or electron beam having a wavelength of i-line or shorter as the exposure light. i
With the fine resist pattern formed by using lines, a good T-shaped cross section has not been obtained so far.

Further, by controlling the focus position of the exposure light, the height of the constriction formed in the substrate ground portion of the resist pattern can be adjusted. Specifically, when the focal position is moved to the substrate side, the height of the constriction becomes low, and when the focal position is moved to the side opposite to the substrate, the constriction height becomes high. When the focal position is displayed with the direction approaching the substrate as the reference and the direction away from the substrate as the plus with respect to the resist coating surface as the reference, the focal position is displayed, the focal position is preferably −1 to +10 μm, more preferably −1 to +6 μ.
m. By setting the focus position in such a range, it is possible to easily set the h within the range of the present invention.

(4) Reversal bake (RB) temperature, R
B time As the RB temperature is lowered, a constriction (slit) is formed in the grounded portion of the inverted trapezoidal substrate, the width of the constriction widens, and the cross section changes from the inverted trapezoidal shape to the T-shaped. RB temperature is 100 ~
123 degreeC, especially 100-118 degreeC are preferable. Further, if the RB time is equal to or longer than the predetermined RB time, a constriction (slit) is formed in the grounded portion of the inverted trapezoidal substrate when the RB time is shortened, which promotes the tendency that the cross section changes from the inverted trapezoidal shape to the T-shaped. The RB time is preferably 30 seconds to 13 minutes. If the RB time is too short, the reaction shown in FIG. 11 will not occur.

(5) Flood exposure amount The flood exposure amount has almost no effect on the cross-sectional shape of the resist, but it is usually preferably 100 to 600 mJ / cm ² .

(6) Developing Conditions and Rinse Conditions If the developing solution is an alkaline aqueous solution, it hardly affects the sectional shape of the resist. For example, a phosphate solution,
It may be TMAH or the like. The higher the temperature of the developer, the more
As the developing time is longer, a constriction (slit) is more likely to be formed in the grounded portion of the inverted trapezoidal substrate, and the constriction is widened to change the cross section into a T-shape. As the developing solution, it is preferable to use an aqueous solution of phosphate (NanH ₃ -nPO ₄ ) 1 to 3%, the developing temperature is preferably room temperature (20 to 25 ° C.), and the developing time is 30 to 90 seconds. It is preferable. If the rinse liquid is pure water, it hardly affects the cross-sectional shape of the resist regardless of the temperature and rinse time of the rinse liquid. Ultrapure water is preferably used as the rinse liquid, the rinse temperature is preferably room temperature (20 to 25 ° C.), and the rinse time is preferably 10 to 180 seconds.

(7) Baking after development Although a baking step may be provided for drying after development, the baking condition after development has almost no effect on the cross-sectional shape of the resist.

As described above, a resist pattern having a T-shaped cross section can be obtained by various combinations of the conditions of each step in the patterning process of the positive resist corresponding to the image inversion. That is, for example, when exposure is performed with an exposure amount less than the minimum exposure amount at which the resist cross section becomes an inverted trapezoid when a certain reversal bake condition and a development condition are combined, a resist pattern having a T-shaped cross section can be formed. Further, even when reversal baking is performed at a temperature lower than the minimum reversal bake temperature at which the resist cross section becomes an inverted trapezoid when a certain exposure condition and development condition are combined, a resist pattern having a T-shaped cross section can be formed. In order to form a resist pattern having a T-shaped cross section, it is effective to control the exposure amount or the reversal bake temperature as described above, and particularly to control the reversal bake temperature. However, as described above, it is necessary to control various other conditions. Can also obtain a T-shaped cross section having a desired shape.

By using the resist pattern of the present invention described above, a preferable magnetoresistive (MR) type thin film element can be obtained.

FIG. 13 shows an example of the layer structure of a composite thin film magnetic head including a magnetoresistive thin film reproducing head and an inductive thin film recording head, which is an example of the magnetoresistive thin film element of the present invention. In this figure, reference numeral 10
Is a magnetoresistive thin film reproducing head, 11 is a substrate, 12 is an insulating film, 13 is a lower shield layer, 14 is an insulating film, 15 is a magnetoresistive film, and 16 is an MR lead layer (electrode film for magnetoresistive film). , 17 are insulating films. The magnetoresistive thin film reproducing head 10 is combined with the inductive thin film recording head 20 having a conventionally known structure to form a composite head. The inductive type thin film recording head 20 usually includes a lower magnetic pole 21, an insulating film 2
2, an insulating film 23, a coil 24, an upper magnetic pole 25, and a protective layer 26.

A ceramic material such as AlTiC is usually used for the substrate 11.

The insulating film 12 preferably has a film thickness of about 1 to 20 μm and is made of Al ₂ O ₃ , SiO ₂ or the like.

The lower shield layer 13 is made of FeAlSi, N
iFe, CoFe, CoFeNi, FeN, FeZr
It is preferably formed of N, FeTaN, CoZrNb, CoZrTa, or the like, and has a film thickness of 0.1 to
5 μm, particularly 0.5 to 3 μm is preferable.

The insulating film 14 has a film thickness of 100 to 2000A.
To some extent, it is preferably formed of Al ₂ O ₃ , SiO ₂ or the like.

The magnetoresistive effect film 15 may be composed of one magnetic layer, but it is usually preferable to have a multilayer film structure in which a magnetic layer and a nonmagnetic layer are laminated. Examples of the material for the magnetic layer include NiFe, NiFeRh, FeMn, and Ni.
Mn, Co, Fe, NiO, NiFeCr, etc. are preferable. The material of the non-magnetic layer is, for example, Ta or C.
u, Ag and the like are preferable. Examples of the multilayer film structure include a three-layer structure of NiFeRh / Ta / NiFe and Ni
Fe / Cu / NiFe / FeMn, NiFe / Cu / C
o / FeMn, Cu / Co / Cu / NiFe, Fe / C
It is preferable that a multi-layer structure such as r, Co / Cu, and Co / Ag is set as one unit, and a plurality of units are repeatedly laminated. Further, when such a multilayer film structure is used, the thickness of the magnetic layer is 5 to 500 A, especially 10 to 2 A.
It is preferably 50A. The thickness of the non-magnetic layer is 5 to
It is preferably 500 A, particularly 10 to 250 A.
The number of repetitions of the above unit is 1 to 30 times, especially 1 to 2 times.
0 times is preferred. The total thickness of the magnetoresistive effect film is preferably 50 to 1000A, particularly 100 to 600A.

The MR lead layer 16 is made of W, Cu, Au, A.
It is preferably formed of g, Ta, Mo, CoPt, or the like, and the film thickness thereof is 100 to 5000 A, particularly 500 to 3A.
000A is preferred.

The insulating film 17 is made of Al ₂ O ₃ or SiO ₂
And the like, and the film thickness is 50 to 5
000 A, especially 100 to 2000 A is preferred.

Of the layers constituting the magnetoresistive thin film head, the insulating films 12, 14, 17 and the magnetoresistive film 15 are included.
The MR lead layer 16 and the MR lead layer 16 can be formed by the lift-off method or the milling patterning method using the resist pattern of the present invention described above. On the other hand, the lower shield layer 13 having a large film thickness can be formed by the above-mentioned milling patterning method using the resist pattern of the present invention described above.

When a continuous film of the magnetoresistive film 15 and the MR lead layer 16 is formed, the above-described lift-off method and milling patterning method are used in combination with the resist pattern of the present invention. You can use it.

By using the resist pattern of the present invention, the magnetoresistive thin film head as described above can be manufactured efficiently and with a high yield.

[0083]

EXAMPLES Specific examples of the present invention will be described below.

In the examples described below, the resist AZ5214E was used as the positive resist corresponding to the image inversion.
(A positive resist containing a mixture of an alkali-soluble phenolic resin and naphthoquinonediazide, a basic amine was added as a negative working agent, and propylene glycol monomethyl ether acetate was used as a main solvent. The rate is 28.
3%) was used.

<Example 1> Resist pattern sample Nos. 1 to 8 shown in Table 2 were prepared. The production conditions of each sample are shown in Tables 1 and 2. Table 1 shows the conditions common to all the samples, and Table 2 shows the exposure amount, the focus position and the RB temperature which differ depending on the samples. Each sample should be 100% within the range of each manufacturing condition.
0 pieces were produced.

[0086]

[Table 1]

[0087]

[Table 2]

With respect to these samples, the above α and h were measured using a field emission electron beam type SEM (Hitachi ULSI high-accuracy appearance dimension evaluation device S-7000) manufactured by Hitachi. The results are shown in Table 2 above. Also sample
When W, T, β, γ, Hw, and Vw were measured for No. 3, W was about 0.75 μm, T was about 1.8 μm,
β is about 135 °, γ is about 90 °, Hw is about 2.4 μm,
Vw / Hw was about 0.3. In addition, as a result of performing similar measurement on other samples, equivalent results were obtained.

Further, a photograph of the cross section of Sample No. 3 taken by using the above SEM is shown in FIG. As can be seen from this photograph, a resist pattern having a T-shaped cross section with good contrast is obtained. For the formation of the resist pattern shown in FIG. 14, an easily cut Si substrate (having an Al ₂ O ₃ layer formed on the surface) was used.

The samples were formed on Al ₂ O ₃ which is a metal oxide (the substrate itself is AlTiC, but the surface of the substrate is Al ₂ O ₃ ).
Ni, Cr, Ta which is a metal, Fe-Ni which is an alloy,
Fe-Ni-Co, LiNbO ₃ is a composite metal oxide
When a resist pattern was formed in the same manner as in Sample No. 3 except for the above, values similar to the values of α and h in Table 2 were obtained, and in this case as well, a T-shaped cross section of good contrast was obtained. It was confirmed that a resist pattern could be obtained.

The following experiment was conducted to examine the effect of milling patterning using the resist pattern of each sample.

On the surface of an AlTiC substrate having an Al ₂ O ₃ film on its surface, NiFe having a film thickness of 0.06 μm was uniformly formed by a sputtering method. Then, the above sample No. 1
Using the lift-off method (the conditions are described below), the milling patterning method (the ion milling conditions are described below) and the combined method (the conditions are described below), each sample is 1000 Magneto-resistive thin film magnetic heads were manufactured individually. The layer structure of these magnetic heads is
As shown in FIG.

Lift-off conditions Organic solvent: acetone Organic solvent immersion time: 30 minutes

Ion milling conditions Ion type: Ar ⁺ gas pressure: 1.5 × 10 ^-1 Torr acceleration voltage: 300 V acceleration current: 250 mA milling angle: 90 ° (relative to substrate surface) time: 8 minutes

Combined use method conditions Combined use of the above ion milling conditions and lift-off conditions

With respect to the obtained magnetoresistive thin film magnetic head, the defective product rate was examined based on the appearance inspection and the electromagnetic conversion characteristics. The results are shown in Table 2 above. From Table 2 above, it can be seen that the magnetic head manufactured using the sample of the present invention in which α and h are in the predetermined range has a remarkably low defective rate.

When manufacturing these magnetic heads,
Of the layers shown in FIG. 13, the shield layer was formed by the milling patterning method, and the continuous film of the magnetoresistive effect film and the magnetoresistive effect electrode film was formed by the combined method. However, even when the magnetoresistive effect film was formed by the milling patterning method and the magnetoresistive effect electrode film was formed by the lift-off method, the same result was obtained.

Example 2 A resist pattern sample was prepared under the conditions shown in Table 3 below.

[0099]

[Table 3]

When the cross section of this sample was measured by the above SEM in the same manner as in Example 1, α was about 0 °, h was about 0.02 μm, W was about 0.26 μm, and T was about 0.5 μm.
m, β is about 80 °, γ is about 70 °, Hw is about 0.65μ
m and Vw / Hw were about 0.21.

A SEM photograph of this sample is shown in FIG.

The following experiment was conducted in order to examine the effect of patterning a film using this resist pattern sample.

A magnetoresistive film (MR film) having a multilayer film structure is formed on the surface of an AlTiC substrate having an Al ₂ O ₃ film on the surface.
Was formed by a sputtering method. The composition and thickness of the MR film are NiFeRh / Ta / NiFe / Ta = 130/100
/ 200/50 (A). Next, the resist pattern sample was provided as a resist cover on the MR film, and patterning was performed by a milling method. Subsequently, without removing the resist cover, a magnetoresistive effect electrode film (MR lead layer) having a multilayer film structure was formed by a lift-off method to obtain a continuous film of the MR film and the MR lead layer. The composition and thickness of the MR lead layer are TiW / CoPt / TiW / Ta = 100/500/1
00/1000 (A). A photograph of this continuous film by the above SEM is shown in FIG. In this continuous film, the width of the MR film (track width when applied to a magnetic head) was 0.36 μm.

When 1000 magnetoresistive thin-film magnetic heads were manufactured in the same manner as this method and the defective product ratio was examined in the same manner as in Example 1, it was 10% or less. From this result, it is understood that according to the present invention, a magnetoresistive effect type thin film magnetic head having a narrow track width can be stably manufactured.

[0105]

【The invention's effect】

(A) By controlling according to the present invention the conditions of the patterning process, which has hitherto been obtained only with an inverted trapezoid,
Even with a single-layer resist, a resist pattern having a T-shaped cross section can be easily formed.

(B) Width of T-shaped cross section of resist pattern,
The width of the grounded portion of the substrate (Vw in FIG. 1), the width of the constriction at the grounded portion of the substrate (W in FIG. 1), and the height of the constriction can be controlled within a certain range with good reproducibility.

(C) When the resist pattern having a T-shaped cross-section patterned according to the present invention is used as a mask pattern for lift-off or dry etching, the cross-sectional shape of the mask pattern becomes a pattern to be patterned by the effect of the above item (B). Since the thickness can be optimized according to the thickness and the patterning width thereof, the yield at the time of lift-off or dry etching is improved.

(D) The width of the resist pattern cross section is 1 μm
The following patterns can also be formed. This allows
Lift-off patterns and dry etching patterns with a width of 1 μm or less can be formed.

(E) By exposure with ultraviolet rays, a resist pattern having a T-shaped cross section can be obtained, and there is no need to use expensive equipment such as an excimer laser, so the equipment cost is low.

(F) Conventionally, in order to form a resist pattern having a T-shaped cross section, it has been necessary to perform an exposure operation that requires mask alignment and a wet development operation a plurality of times, which is very complicated. However, in the present invention, since the exposure work and the development work are each performed once, the patterning work can be simplified and the work time can be shortened.

(G) Due to the effects of the items (E) and (F), the lift-off pattern and the dry etching pattern can be formed at low cost.

[Brief description of drawings]

FIG. 1 is a cross-sectional view for explaining a cross-sectional structure of a resist pattern having a T-shaped cross section according to the present invention.

FIG. 2 is an explanatory diagram of a milling process.

FIG. 3 is an explanatory diagram illustrating a state in which a material to be milled adheres to a resist pattern in a milling process when a resist pattern (resist cover) has an inverted trapezoidal cross section.

FIG. 4 is an explanatory diagram illustrating a state in which a material to be milled is attached to a resist pattern in a milling process when a resist pattern (resist cover) has a T-shaped cross section.

FIG. 5 is an explanatory diagram of a lift-off process.

FIG. 6 is an explanatory diagram illustrating a state in which a material to be patterned is attached to a resist pattern in a lift-off process when a resist pattern (resist cover) has an inverted trapezoidal cross section.

FIG. 7 is an explanatory diagram illustrating a state in which a material to be patterned is attached to a resist pattern in a lift-off process when a resist pattern (resist cover) has a T-shaped cross section.

FIG. 8 is an explanatory diagram of a combined method of a milling method and a lift-off method.

FIG. 9 shows α and h in the resist pattern of the present invention.
It is a graph which shows the range of.

FIG. 10 is an explanatory diagram illustrating a patterning process of a positive resist corresponding to image inversion.

FIG. 11 is a diagram illustrating an example of a chemical reaction that occurs in a resist in the patterning process of a positive resist corresponding to image inversion.

FIG. 12 is an explanatory diagram for explaining the influence of the condition of each step on the cross-sectional shape of the resist when other conditions are the same in the patterning process of the positive resist corresponding to the image inversion.

FIG. 13 is a cross-sectional view showing the layer structure of a magnetoresistive effect thin film head manufactured using the resist pattern of the present invention.

FIG. 14 is a drawing-substitute photograph showing a fine pattern formed on a substrate, which is an example sample No. 3 of the present invention.
3 is an SEM photograph showing a cross-sectional structure of the resist pattern of FIG.

FIG. 15 is a drawing-substituting photograph showing a fine pattern formed on a substrate, which is an SEM photograph showing a cross-sectional structure of the resist pattern produced in Example 2.

16 is a drawing-substituting photograph showing a fine pattern formed on a substrate, in which the MR film and the MR lead layer formed by the combined use of milling and lift-off using the resist pattern of Example 2 are continuous. It is a SEM photograph which shows a film.

FIG. 17 is a drawing-substitute photograph showing a fine pattern formed on a substrate, which is an SEM photograph showing a cross-sectional structure of a conventional resist pattern.

FIG. 18 is a drawing-substituting photograph showing a fine pattern formed on a substrate, which is an SEM photograph showing a cross-sectional structure of a conventional resist pattern.

FIG. 19 is a drawing-substituting photograph showing a fine pattern formed on a substrate, which is an SEM photograph showing a cross-sectional structure of a conventional resist pattern.

FIG. 20 is a drawing-substitute photograph showing a fine pattern formed on a substrate, which is an SEM photograph showing a cross-sectional structure of a conventional resist pattern.

[Explanation of symbols]

 1 Substrate 2 Image Reversal Positive Resist 3 Mask A, B Ultraviolet

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H01L 21/306 H01L 21/302 C 43/08 21/306 D

Claims (14)

[Claims] 1. A substantially homogeneous film formed by using a resist agent having an image reversal function by adding a negative working agent to a positive resist containing a mixture of an alkali-soluble phenol resin and naphthoquinonediazide. A resist pattern, a vertical bar portion whose cross-sectional shape extends upward from the substrate surface to form a substantially T-shaped vertical bar portion, and a state in which the vertical bar portion is continuous with and spaced from the substrate surface. A T-shape having a horizontal bar portion that extends laterally and constitutes a substantially T-shaped horizontal bar portion, and in the cross-sectional shape, a minimum value of angles formed by the tangent line of the lower edge of the horizontal bar portion and the substrate surface. Is α, and the intersection W of the perpendicular line drawn from the outermost edge of the horizontal bar portion to the substrate surface and the substrate surface
o and h is the distance between the lower edge of the horizontal bar portion and the substrate surface at the intermediate position between the point Wi where the vertical bar portion side edge on the outermost edge side contacts the substrate surface, then α and h in the h-α graph h is A: α = 0 °, h = 0.01 μm, B: α = 20 °, h = 0.01 μm, C: α = 20 °, h = 0.2 μm, D: α = 0 °, h = A resist pattern with a T-shaped cross section existing within (including on the side of) a quadrangle that connects four points of 0.3 μm in this order. 2. In the h-α graph, α and h are A: α = 0 °, h = 0.01 μm, X: α = 5 °, h = 0.01 μm, Y: α = 5 °, h = 0.15 μm, Z: α = 0 °, h = 0.15 μm existing in a range surrounded by a quadrilateral connecting four points in this order (including on the side). Resist pattern. 3. In the h-α graph, α and h are A: α = 0 °, h = 0.01 μm, X: α = 5 °, h = 0.01 μm, G: α = 5 °, h = 2. The T-shaped cross-section of claim 1 existing within a range surrounded by a quadrangle connecting 0.1 points of 0.1 μm, H: α = 0 °, and h = 0.1 μm in this order. Resist pattern. 4. A distance between an intersection point Wo of a perpendicular line drawn from the outermost edge of the horizontal bar portion to the substrate surface and the substrate surface and a point Wi at which the side edge of the vertical bar portion on the outermost edge side and the substrate surface are in contact with each other is W. The resist pattern having a T-shaped cross section according to claim 1, wherein W = 0.03 to 3 μm. 5. The resist pattern having a T-shaped cross section according to claim 1, wherein Hw = 0.1 to 7 μm, where Hw is the maximum width of the horizontal bar portion. 6. The resist pattern having a T-shaped cross section according to claim 5, wherein Vw / Hw = 0.1 to 0.995, where Vw is a width of a region where the vertical bar portion is in contact with the substrate surface. 7. The resist pattern having a T-shaped cross section according to claim 1, wherein the surface is formed on the surface of a substrate made of a metal material or a ceramic material. 8. A resist coating composition containing a mixture of an alkali-soluble phenolic resin and naphthoquinonediazide, which is added with a negative working agent to give an image reversal function. When manufacturing a resist pattern by a patterning process that has each step of reversal bake and development in this order, under the condition that a resist pattern with an inverted trapezoidal cross section can be obtained, the thickness of the resist coating film and the exposure dose decrease. By lowering the reversal bake temperature, shortening the reversal bake time, increasing the developer temperature and prolonging the developing time, at least one condition change is added,
A method of manufacturing a resist pattern having a T-shaped cross section, which enables manufacturing of a resist pattern having a T-shaped cross section. 9. When the focus position when exposing a resist coating film is displayed with the direction approaching the substrate as the minus side and the direction away from the substrate as the plus side based on the resist coating surface as the reference, the focus position is −1 to +10 μm. 9. The method for manufacturing a resist pattern having a T-shaped cross section according to claim 8. 10. A reversal bake at 100 to 123 ° C.
10. The T according to claim 8 or 9, which is performed at the temperature of 30 seconds to 13 minutes.
A method of manufacturing a resist pattern having a shaped cross section. 11. A method of manufacturing a resist pattern having a T-shaped cross section according to claim 8, wherein the resist pattern having a T-shaped cross section according to claim 1 is manufactured. 12. At least one layer of a magnetoresistive effect film and an electrode film for a magnetoresistive effect film is formed by a lift-off method using a resist pattern having a T-shaped cross section according to claim 1 as a resist cover. A magnetoresistive thin film element. 13. At least one layer of a magnetoresistive film, an electrode film for a magnetoresistive film, and a shield film by a milling patterning method using the resist pattern having the T-shaped cross section according to claim 1 as a resist cover. A magnetoresistive effect thin film element in which a film is formed. 14. A magnetoresistive effect film and an electrode film for a magnetoresistive effect film by using the resist pattern having a T-shaped cross section according to claim 1 as a resist cover and using a combined method of a milling patterning method and a lift-off method. A magnetoresistive effect type thin film element having a continuous film formed with.