JPH07325383A - Halftone type phase shift mask, material to form translucent part to be used for production of halftone type phase shift mask, and production of halftone type phase shift mask - Google Patents

Abstract

PURPOSE:To provide a halftone phase shift mask which can be easily produced and can be easily used, a material which forms a translucent part to be used for the production of the halftone phase shift mask, and the production method of the halftone phase shift mask. CONSTITUTION:(1) The material to form a translucent part for the production of a halftone phase shift mask consists of SOG containing a dye and a photosensitive agent, a photosensitive polyimide containing die, or the like. The material has absorption for exposure light and photosensitivity or sensitivity for radiation and has phase shifting property to shift the phase of exposure light transmitting through the material. (2) The halftone phase shift exposure mask has a light transmitting part 2a and a translucent part 3a. The translucent part consists of the material of (1). (3) The halftone phase shift exposure mask is produced by (I) forming a film of the material (1) on a transparent substrate 1, exposing the film with light or radiation in a pattern, and (II) developing to obtain a desired pattern.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a halftone type phase shift mask, a semitransparent portion forming material used for producing a halftone type phase shift mask, and a method for producing a halftone type phase shift mask.

[0002]

2. Description of the Related Art A phase shift mask having a light transmitting portion and a semi-transparent portion (also referred to as a semi-shielding portion) has been conventionally known. This type is called a halftone type phase shift mask. This kind of phase shift mask
Usually, it is composed of an opening forming a light transmitting portion and a semi-transparent portion having a slight light transmittance, so that the transmitted light of these two portions has a phase difference, usually preferably a phase difference of 180 °. , A shifter is provided.

Such a halftone type phase shift mask is attracting attention because it is easy to manufacture among the phase shift masks. That is, since the halftone type phase shift mask does not require double writing unlike the conventionally proposed outrigger type and rim type phase shift masks, there is no concern about the influence of misalignment due to that.
The D process and the mask manufacturing process are very easy.

In addition, the halftone type phase shift technique has an advantage that it is extremely effective in improving the resolution and depth of focus of an isolated pattern such as a contact hole pattern.

In the prior art, the halftone type phase shift exposure mask is a light-shielding film (semi-light-shielding film) made of a thin semi-transparent Cr film which has a light transmittance of a few percent to a few tens of percent and which slightly transmits the exposure light. In many cases, it was proposed in the form used as (). The phase difference is that SiO is formed on the semi-shielding film (Cr, etc.).
_When obtained by applying a transparent film such as ₂ shifter material,
In some cases, the base material may be directly obtained by etching or the like.

For example, in a typical method of manufacturing a halftone type phase shift exposure mask, as shown in FIGS. 2 to 7, a transparent substrate 1 made of quartz or the like (see FIG. 2. In this case, transparency means On the other hand, the substrate 1 is semi-transparent (semi-transparent in this case) having a predetermined transmittance, in contrast to exposure light used for mask patterning using a finished phase shift mask. Is also semi-transparent to the exposure light when using the finished phase shift mask). (FIG. 3), and then, a transparent film (SOG or sputter CVD SiO ₂ film) 6 to be a shifter is formed (FIG. 4), and an EB resist 7 is applied thereon (FIG. 5). exposure Resist patterns 7a and 7b are formed by development or the like (FIG. 6), and then etching is sequentially performed to form light transmitting portions 2a to 2c, patterned light shielding material 5a and 5b, and transparent shifter as shown in FIG. A phase shift exposure mask having semitransparent portions 3a and 3b composed of films 6a and 6b is provided. It can be said that the etching at the time of fabrication is not always easy, and rather difficult at each stage.

Because of the complexity of the above method, a material film having both properties of translucency and phase shift has been proposed, which is called an αLH film (A. Callegari). , AT Pomeren
e, H .; J. Hovel, D.M. Babich, S .; Pu
rusthoman, and J. et al. M. Shaw
"Optical properties of hy
drowned amorphous-carb
on film for attended ph
ase-shift mask applicatio
ns ”).

When this is used, as shown in FIG.
A phase-shifting semitransparent film 6'is formed on the transparent substrate 1 (step I '), and a resist 7 is applied thereon (step II'),
The resist patterns 7a and 7b are obtained by drawing, developing, and rinsing the patterns, and the phase shift semitransparent film 6'is patterned using the resist patterns 7a and 7b as masks.
And the patterned phase shift semi-transparent film 6'a,
The phase shift mask has semi-transparent portions 3a and 2b made of 6'b. Although this method is somewhat simple in process, it still requires etching, and requires complicated and difficult steps.

[0009]

An object of the present invention is to eliminate the complexity of the processes of the prior art as described above, and to easily carry out the halftone type phase shift mask, the semitransparent portion forming material used for producing the halftone type phase shift mask, And a method for manufacturing a halftone type phase shift mask.

[0010]

The invention according to claim 1 of the present application is a halftone type phase shift exposure mask comprising a light transmitting portion and a semitransparent portion, which has absorption for exposure light, and A halftone phase shift mask, characterized in that the semitransparent portion is formed of a material having photosensitivity or radiation sensitivity and having a phase shift property of shifting the phase of the transmitted exposure light, This achieves the above object.

The invention according to claim 2 of the present application is characterized in that the semi-transparent portion forming material is an SOG which imparts absorptivity to exposure light and imparts photosensitivity or radiation sensitivity. The halftone phase shift mask according to item 1, which achieves the above object.

The invention according to claim 3 of the present application is the halftone type phase shift mask according to claim 2, wherein the absorptivity of the SOG to the exposure light is imparted by a die. Thus, the above object is achieved.

The invention according to claim 4 of the present application is the halftone type according to claim 2 or 3, characterized in that the photosensitivity or radiation sensitivity of the SOG is imparted by an acid generator. A phase shift mask for achieving the above object.

In the invention of claim 5 of the present application, the translucent portion forming material has a film thickness t represented by t = λ (1 + 2m) / 2 (n-1) (where m is a positive integer, n The halftone phase shift mask according to any one of claims 1 to 4, wherein the halftone phase shift mask is formed of a material having a refractive index of a semitransparent portion forming material. .

The invention of claim 6 of the present application is characterized in that the semi-transparent portion forming material is a photosensitive polyimide which imparts absorptivity to exposure light and has photosensitivity or radiation sensitivity. The halftone type phase shift mask according to item 1, which achieves the above object.

The invention according to claim 7 of the present application is the halftone type phase shift mask according to claim 5, characterized in that the absorptivity to the polyimide exposure light is imparted by a die. This achieves the above-mentioned object.

The invention according to claim 8 of the present application comprises: a light transmitting portion;
A semi-transparent portion forming material used for producing a halftone type phase shift exposure mask having a semi-transparent portion, which has absorption of exposure light, has photosensitivity or radiation sensitivity, and has passed through the exposure light. The semitransparent portion for producing a halftone type phase shift mask, which has a phase shifting property of shifting the phase of, is a forming material, and thereby achieves the above object.

The invention according to claim 9 of the present application is characterized in that the semi-transparent portion forming material is an SOG which imparts absorptivity to exposure light and imparts photosensitivity or radiation sensitivity. The material for forming a semi-transparent portion for producing the halftone type phase shift mask according to Item 7, which achieves the above object.

The invention of claim 10 of the present application is the above SOG.
3. The semitransparent portion forming material for producing a halftone type phase shift mask according to claim 2, wherein the absorptivity to the exposure light is imparted by a die. To achieve.

The invention of claim 11 of the present application is the above SOG.
10. The halftone type phase shift mask according to claim 8 or 9, wherein the photosensitivity or radiation sensitivity of is imparted by an acid generator. Is.

The invention of claim 12 of the present application is characterized in that the semi-transparent portion forming material is a photosensitive polyimide which imparts absorptivity to exposure light and has photosensitivity or radiation sensitivity. The halftone phase shift mask according to item 7, which achieves the above object.

A thirteenth aspect of the present invention is the halftone type phase shift mask according to the eleventh aspect, wherein the absorptivity to the polyimide exposure light is imparted by a die. This achieves the above-mentioned object.

A fourteenth aspect of the present invention is directed to a method of manufacturing a halftone type phase shift exposure mask having a light transmitting portion and a semitransparent portion, which has absorption of exposure light and is photosensitive or A semi-transparent part forming material having a radiation sensitivity and a phase shift property that shifts the phase of transmitted exposure light is formed on a transparent substrate, and this is exposed to a pattern by light or radiation and developed. A semi-transparent portion having a desired pattern is thereby formed, which is a method of manufacturing a halftone type phase shift exposure mask, which achieves the above object.

The invention according to claim 15 of the present application is characterized in that the semi-transparent portion forming material is an SOG which imparts absorptivity to exposure light and imparts photosensitivity or radiation sensitivity. The method for producing a halftone type phase shift mask according to Item 14, which achieves the above object.

The invention of claim 16 of the present application is the above SOG.
15. The method for manufacturing a halftone type phase shift mask according to claim 14, wherein the absorptivity to the exposure light is imparted by a die. .

The invention of claim 17 of the present application is the above SOG.
16. The photosensitivity or radiation sensitivity of (1) is imparted by a photo-acid generator.
The method for producing a halftone phase shift mask according to Item 6, which achieves the above object.

The invention of claim 18 of the present application is characterized in that the semi-transparent portion forming material is a photosensitive polyimide which imparts absorptivity to exposure light and has photosensitivity or radiation sensitivity. Item 15. A method of manufacturing a halftone phase shift mask according to Item 14, which achieves the above object.

According to a nineteenth aspect of the present invention, the method for producing a halftone phase shift mask according to the eighteenth aspect is characterized in that the absorption of the polyimide exposure light is imparted by a die. Therefore, the above object is achieved thereby.

According to a twentieth aspect of the invention of the present application, the semitransparent portion forming material has a final film thickness t represented by t = λ (1 + 2m) / 2 (n-1) (where m is a positive integer). , N is formed so as to have a refractive index of a semi-transparent portion forming material). The halftone type phase shift mask according to claim 14, wherein Is achieved.

In a preferred embodiment of the present invention, the final film thickness is t = λ (1 + 2m) / 2 (n−) using a photosensitive or radioactive resin whose refractive index after pattern formation is n.
1) With an initial film thickness (m is a positive integer) (a little thicker in consideration of the amount of film slippage due to development), first create a shifter / semitransparent film on the quartz substrate with a semitransparent portion forming material, This is subjected to post-exposure development rinsing and baking with a drawing device, a laser, or an optical drawing device to produce a phase shift mask. At this time, the semitransparent film finally formed preferably has a transmittance of 5 to 25%.

The semi-transparent photosensitive or radiation-sensitive composition which can be used for the above-mentioned pattern formation is SOG which is photosensitive or radiation-sensitive.
Alternatively, photosensitive polyimide is preferably used, and in order to make it semitransparent, it is easy to add a die (dye). A phthalocyanine derivative or the like is most suitable for this die.

The present invention uses a die-incorporated SOG or a die-incorporated photosensitive polyimide which has a pattern forming ability and is semitransparent (for example, preferably has a transmittance of 5 to 25% at the exposure wavelength at the finish). Then, a semitransparent film which also serves as a shifter is directly formed by EB drawing or laser drawing.

The transparency of the semi-transparent part forming material needs to be adjusted by the exposure wavelength used, and this can be adjusted by the addition amount of the die. When used as a phase shift exposure mask, the exposure wavelength used is preferably 248 nm (KrF), 193 nm (ArF), 157.
nm (F ₂ ) or the spectrum of an ultra-high pressure mercury lamp in these regions (near 254 nm), and therefore, a material that does not change sufficiently in these wavelength regions for both the semitransparent portion forming material and the die is desirable. Therefore, as a material, SOG
Alternatively, photosensitive polyimide having high heat resistance and environment resistance is preferable. Among them, SOG is the most excellent. Also for the die, a normal organic substance is transformed by the light in the DeepUV region, and therefore phthalocyanine and the like are very good. Deep
It is difficult to change even if it is exposed to UV, and it dissolves well in a solvent.

In order to impart the pattern forming ability to SOG, its siloxane forming ability (dehydration condensation) can be utilized. Therefore, an acid generator that generates an acid by light or radiation is included. For example, a photoacid generator such as triphenylsulfonium triflate, a sulfonate derivative, or an organic halide is contained.

In the present invention, SOG means a substance which can be applied and can obtain SiO ₂ by baking after application, and usually, when dissolved in a solvent,
Make it coatable. Generally, a material containing silicon (for example, in the form of a silanol group), which can be applied by being dissolved in a solvent such as an organic solvent is preferably used. As the SOG component, silanol Si (OH) ₄ is used as ethyl alcohol C ₂
Dissolved in H ₅ OH, organosilanol R _m
Butyl cellosolve H with Si (OH) _4-n (n is 1 to 3)
Those formed by dissolving the _{OCH 2 CH 2 OC 4 H 9} , or organopolysiloxane siloxy San HOSi (CH _{3) 2} -
_{(CH 3 -Si-CH 3)} n -Si (CH 3) 2 OH,
Silanol oligomers part trimethylsilyl group protection _{(HO) 3 Si- (Si (} OSi≡) 2) n -Si (O
H) ₃ , or those containing a polymer such as organosylcerquioxane as a component. SOG
Has been widely used in the conventional phase shift mask forming process technology, and has the advantages that it is easy to use, rich in workability, and easy to obtain.

[0036]

EXAMPLES The present invention will be described below with reference to specific examples. However, as a matter of course, the present invention is not limited to the examples described below.

Example 1 In this example, the present invention was applied to an exposure mask for pattern formation of a miniaturized and integrated semiconductor device. (1) Preparation of Translucent Part Forming Material (Sensitive SOG) Diphenyliodonium triflate was added to SOGSF2700 manufactured by Sumitomo Chemical Co., Ltd. as an acid generator to generate an acid by radiation in a proportion of 5 wt% with respect to the solid content. In addition, as a die, 1 wt% of tetramethoxycopper phthalocyanine was added and dissolved, followed by filtration.

As shown schematically in FIG. 1, the transparent substrate 1
Spin coating on a quartz substrate. After coating, bake at 100 ° C for 60 seconds and then at 150 ° C for 60 seconds to obtain a film thickness of 252
A semi-transparent part forming material film 4 having a thickness of nm was formed (step I). This is subjected to a drawing step IIa for drawing a large evaluation pattern using an EB drawing device (JB-5FE manufactured by NEC), followed by development IIb for 60 seconds with ethyl alcohol and rinse IIc with hexane for 60 seconds. Done and then dried.

The translucent portion forming materials 4a and 4b thus obtained have a transmittance of 90% with respect to exposure light having a wavelength of 248 nm, a formed film thickness of 243 nm (measured by Trank step of Rank Taylor Hobson), and a spectral refractive index (of Sopra) (Measured with the Moss system), the real part n = 1.51. Therefore, the film slip is about 10 nm. In this way, a halftone phase shift exposure mask including the light transmitting portions 2a to 2c and the semitransparent portions 3a and 3b as shown in FIG.
A material (semitransparent portion forming material) 4 that has absorption of exposure light, has photosensitivity or radiation sensitivity, and has a phase shift property of shifting the phase of the transmitted exposure light.
A halftone type phase shift mask in which the semitransparent portions 3a and 3b were formed by a and 4b was obtained.

(2) Fabrication of evaluation pattern Using the same process as above, 0.4 μm,
Contact hole patterns of 0.35 μm and 0.3 μm were formed.

1 μm of this on a 5-inch silicon wafer
A wafer coated with a thick chemically amplified positive resist (prototype), NSR1505EX (NA: 0.42, σ: 0.
The exposure experiment was performed in 5). As a reference, an ordinary chrome mask (a mask having only light transmission and a light shielding portion made of chrome) was used.

[Table 1]

According to this embodiment, a phase shift mask having a large degree of freedom in defocus latitude can be obtained by an extremely easy process that does not require etching. That is, the present embodiment is a simple process using the above steps,
It is possible to manufacture a halftone phase shift mask, and it is possible to form a finer pattern by exposure with a wider focus margin.

Example 2 In this example, a halftone type phase shift mask was manufactured with the same configuration as in Example 1 except that photosensitive polyimide was used as the material for forming the semitransparent portion.

The photosensitive polyimide used in this example is specifically marketed under the trade name "Photo Nice" (Toray Industries, Inc.). This "photo nice"
Is a salt group into which a photosensitive group has been introduced.
COOH and -CONHR ¹ NH- bond to each other, and this -CO
R ² NR ³ ₂ is assumed to bind to OH (Asano "photosensitive polyimide coating agent" Photoneece ""
(Poly File Vol. 27, No. 2, 1990, 2
Page 5 ~)).

In this example, phthalocyanines were used as a die to impart "photonice" with absorptivity (semitransparency) for exposure light. Specifically, Example 1
The same tetramethoxy copper phthalocyanine can be used as in Example 1. The final film thickness t is t =
λ (1 + 2m) / 2 (n-1) (however, m
Is a positive integer, n is the refractive index of a photonice containing a die, and applied to a quartz substrate which is a transparent substrate by a spinner (final film loss was about 50%).

After coating, a semitransparent forming material film was formed by prebaking with a hot plate, and this was exposed with a g-line stepper. Dip development was performed using a dedicated developer DV series, rinsed with isopropyl alcohol for 60 seconds, and then dried.

A halftone phase shift mask was prepared in the same manner as in Example 1 using the obtained semitransparent portion forming material.
As a result of evaluation, the same effect as in Example 1 could be obtained. According to this example, a halftone type phase shift mask having a semi-transparent portion excellent in heat resistance, mechanical toughness and adhesiveness, which are advantages of the polyimide material, was obtained.

According to the present invention, a halftone type phase shift mask which does not require a complicated process and can be easily implemented, a semitransparent portion forming material used for producing a halftone type phase shift mask, and a halftone type It was possible to provide a method for manufacturing a phase shift mask.

[Brief description of drawings]

FIG. 1 is a diagram showing a process of Example 1.

FIG. 2 is a diagram showing a process of a conventional example (1).

FIG. 3 is a diagram showing a process of a conventional example (1).

FIG. 4 is a diagram showing a process of the conventional example (1).

FIG. 5 is a diagram showing a process of a conventional example (1).

FIG. 6 is a diagram showing a process of a conventional example (1).

FIG. 7 is a diagram showing a process of a conventional example (1).

FIG. 8 is a diagram showing a process of a conventional example (2).

[Explanation of symbols]

 1 Transparent Substrate (Quartz Substrate) 2a to 2c Light Transmitting Part 3a, 3b Semi-Transparent Part 4, 4a, 4b Semi-Transparent Part

Claims (20)

[Claims] 1. A halftone type phase shift exposure mask comprising a light-transmitting portion and a semi-transparent portion, which has absorption for exposure light and has photosensitivity or radiation sensitivity and which is transmitted. A halftone type phase shift mask, wherein a semitransparent portion is formed of a material having a phase shift property for shifting the phase of light. 2. The halftone phase according to claim 1, wherein the semi-transparent part forming material is SOG which is provided with absorptivity for exposure light and is provided with photosensitivity or radiation sensitivity. Shift mask. 3. The halftone type phase shift mask according to claim 2, wherein the absorptivity of the SOG for exposure light is imparted by a die. 4. The halftone type phase shift mask according to claim 2, wherein the photosensitivity or radiation sensitivity of the SOG is imparted by an acid generator. 5. The translucent portion forming material is t = λ (1 + 2)
The film thickness t represented by m) / 2 (n-1) (where m is a positive integer and n is the refractive index of the semitransparent portion forming material). The halftone phase shift mask according to any one of 1. 6. The semi-transparent portion forming material is a photosensitive polyimide that imparts absorptivity to exposure light and has photosensitivity or radiation sensitivity.
The halftone phase shift mask described in. 7. The absorptivity for the polyimide exposure light is:
The halftone phase shift mask according to claim 5, wherein the halftone phase shift mask is provided by a die. 8. A semi-transparent part forming material used for producing a halftone type phase shift exposure mask comprising a light-transmitting part and a semi-transparent part, the semi-transparent part forming material having absorption of exposure light and being photosensitive or radiation sensitive. A material for forming a semi-transparent portion for producing a halftone phase shift mask, which has a property of shifting the phase of the transmitted exposure light. 9. The halftone phase according to claim 7, wherein the semi-transparent part forming material is SOG which is provided with absorptivity for exposure light and is provided with photosensitivity or radiation sensitivity. Semi-transparent part forming material for shift mask fabrication. 10. The absorptivity of the SOG for exposure light is:
The material for forming a semitransparent portion for producing a halftone type phase shift mask according to claim 2, which is provided by a die. 11. The halftone type phase shift mask according to claim 8, wherein the photosensitivity or radiation sensitivity of the SOG is imparted by an acid generator. 12. The halftone type according to claim 7, wherein the material for forming the semitransparent portion is a photosensitive polyimide that imparts absorptivity to exposure light and has photosensitivity or radiation sensitivity. Phase shift mask. 13. The halftone type phase shift mask according to claim 11, wherein the absorptivity to the polyimide exposure light is imparted by a die. 14. A method of manufacturing a halftone type phase shift exposure mask comprising a light transmissive portion and a semitransparent portion, which has absorption of exposure light and is photosensitive or radiation sensitive, and A semi-transparent portion having a desired pattern is formed by forming a film of a semi-transparent portion forming material having a phase shift property that shifts the phase of the transmitted exposure light on a transparent substrate, exposing this to a pattern with light or radiation, and developing. A method of manufacturing a halftone type phase shift exposure mask, which comprises: 15. The halftone phase according to claim 14, wherein the semi-transparent portion forming material is SOG which is provided with absorptivity for exposure light and is also provided with photosensitivity or radiation sensitivity. Method for manufacturing shift mask. 16. The absorptivity of the SOG for exposure light is:
The halftone phase shift mask manufacturing method according to claim 14, wherein the halftone phase shift mask is provided by a die. 17. The method for producing a halftone type phase shift mask according to claim 15, wherein the photosensitivity or radiation sensitivity of the SOG is imparted by a photoacid generator. 18. The halftone type according to claim 14, wherein the semi-transparent portion forming material is a photosensitive polyimide that imparts absorptivity to exposure light and has photosensitivity or radiation sensitivity. Method for manufacturing phase shift mask. 19. The method of manufacturing a halftone type phase shift mask according to claim 18, wherein the absorptivity to the polyimide exposure light is imparted by a die. 20. The translucent portion forming material is t = λ (1+
A film thickness t represented by 2m) / 2 (n-1) (where m is a positive integer and n is a refractive index of the semitransparent portion forming material). Item 14 to 17
The halftone phase shift mask according to any one of 1.