CN-114545726-B - Phase shift mask, back plane thereof, phase shift mask and method for manufacturing display device

CN114545726BCN 114545726 BCN114545726 BCN 114545726BCN-114545726-B

Abstract

Provided is a phase shift mask chassis which can suppress fluctuation in transmittance with respect to a representative wavelength of exposure light and has a desirably high transmittance and can perform good pattern transfer even when film thickness fluctuation occurs in a phase shift film. The phase shift mask base plate has a phase shift film on a transparent substrate, the phase shift film having a transmittance of 30% or more and 80% or less at a representative wavelength of an exposure wavelength, an attenuation coefficient k of 0.10 or more and 0.25 or less, a refractive index n of 2.20 or more and 2.57 or less, the representative wavelength of the exposure wavelength being in a range of 313 to 436nm, the representative wavelength being located between a valley of a surface reflectance on an adjacent short wavelength side and a peak of a surface reflectance on an adjacent long wavelength side in a relationship between the surface reflectance of the phase shift film and the wavelength, and the phase shift film containing a transition metal and silicon.

Inventors

Tian Biansheng
ASAKAWA KEIJI
An Senshunyi

Assignees

HOYA株式会社
HOYA株式会社

Dates

Publication Date: 20260421
Application Date: 20211117
Priority Date: 20201124

Claims (8)

1. A phase shift mask base plate having a phase shift film on a transparent substrate, characterized in that, The phase shift film has a transmittance of 30 to 80 percent at a wavelength of 405nm, a phase shift amount of 160 to 200 DEG, an attenuation coefficient k of 0.11 to 0.20, a refractive index n of 2.20 to 2.57, The film thickness of the phase shift film is 130nm to 180nm, The phase shift film is a single-layer film, The wavelength of 405nm is located between a valley of the surface reflectivity on the adjacent short wavelength side and a peak of the surface reflectivity on the adjacent long wavelength side in the relationship between the surface reflectivity of the phase shift film and the wavelength, The phase shift film contains a transition metal, silicon and a light element, and the total content of the light element components including oxygen and nitrogen contained therein is 50 at% or more and 65 at% or less, The transition metal is one or more elements selected from molybdenum, zirconium, tantalum, tungsten and titanium, In the phase shift film, when the difference between the maximum value and the minimum value of the transmittance at a wavelength of 405nm is the transmittance fluctuation value when fluctuation occurs in the film thickness within a range of 30nm or less, the ratio of the transmittance fluctuation value to the transmittance at a wavelength of 405nm before fluctuation occurs in the film thickness is 20% or less.
2. The phase shift mask backplane of claim 1 wherein, In the phase shift film, when the film thickness fluctuates in a range of 30nm or less, the difference between the maximum value and the minimum value of the back surface reflectance with respect to the wavelength of 405nm is 10% or more.
3. The phase shift mask backplane of claim 1 wherein, An etching mask film having different etching selectivity with respect to the phase shift film is provided on the phase shift film.
4. A method for manufacturing a phase shift mask, comprising: Preparing the phase shift mask blank according to claim 1 or 2; And forming a resist film on the phase shift film, wherein the phase shift film is wet etched using a resist film pattern formed from the resist film as a mask, and a phase shift film pattern is formed on the transparent substrate.
5. A method for manufacturing a phase shift mask, comprising: a step of preparing the phase shift mask base plate according to claim 3; Forming a resist film on the etching mask film, wet etching the etching mask film using a resist film pattern formed from the resist film as a mask, and forming an etching mask film pattern on the phase shift film; And forming a phase shift film pattern on the transparent substrate by wet etching the phase shift film using the etching mask film pattern as a mask.
6. A phase shift mask having a patterned phase shift film on a transparent substrate, characterized in that, The phase shift film has a transmittance of 30 to 80 percent at a wavelength of 405nm, a phase shift amount of 160 to 200 DEG, an attenuation coefficient k of 0.11 to 0.20, a refractive index n of 2.20 to 2.57, The film thickness of the phase shift film is 130nm to 180nm, The phase shift film is a single-layer film, The wavelength of 405nm is located between a valley of the surface reflectivity on the adjacent short wavelength side and a peak of the surface reflectivity on the adjacent long wavelength side in the relationship between the surface reflectivity of the phase shift film and the wavelength, The phase shift film contains a transition metal, silicon and a light element, and the total content of the light element components including oxygen and nitrogen contained therein is 50 at% or more and 65 at% or less, The transition metal is one or more elements selected from molybdenum, zirconium, tantalum, tungsten and titanium, In the phase shift film, when the difference between the maximum value and the minimum value of the transmittance at a wavelength of 405nm is the transmittance fluctuation value when fluctuation occurs in the film thickness within a range of 30nm or less, the ratio of the transmittance fluctuation value to the transmittance at a wavelength of 405nm before fluctuation occurs in the film thickness is 20% or less.
7. The phase shift mask of claim 6, wherein the phase shift mask is formed by a mask pattern, In the phase shift film, when the film thickness fluctuates in a range of 30nm or less, a difference between a maximum value and a minimum value of the back surface reflectance with respect to the 405nm wavelength is 10% or more.
8. A method for manufacturing a display device, characterized in that, In the exposure step, the phase shift mask obtained by the method for manufacturing a phase shift mask according to claim 4 or 5 or the phase shift mask according to claim 6 or 7 is placed on a mask stage of an exposure apparatus, and a transfer pattern formed on the phase shift mask is transferred to a resist formed on a substrate of a display device by exposure.

Description

Phase shift mask, back plane thereof, phase shift mask and method for manufacturing display device Technical Field The invention relates to a phase shift mask base plate, a phase shift mask, a method for manufacturing the phase shift mask, and a method for manufacturing a display device. Background In recent years, display devices such as FPD (Flat Panel Display) represented by an Organic LIGHT EMITTING Diode (OLED) have been increasingly large in size, have been increasingly wide in viewing angle, have been increasingly high in sharpness, and have been increasingly fast in display speed. As an element required for increasing the definition and the display speed, it is necessary to manufacture an electronic circuit pattern such as a fine element or a wiring having high dimensional accuracy. Patterning of the electronic circuit for the display device is often performed by photolithography. Therefore, there is a need for a phase shift mask for manufacturing a display device, a photolithography mask such as a binary mask, and the like, in which a fine and high-precision pattern is formed. For example, patent document 1 discloses a phase shift mask in which a mask pattern formed on a transparent substrate is formed by a light transmission portion that transmits light of an intensity substantially contributing to exposure and a light semi-transmission portion that transmits light of an intensity substantially not contributing to exposure, and in which the phase of light passing through the light semi-transmission portion is shifted to be different from the phase of light passing through the light transmission portion, so that light near a boundary portion between the light transmission portion and the light semi-transmission portion is offset from each other, whereby the contrast of the boundary portion can be maintained satisfactorily. Prior art literature Patent literature Patent document 1 Japanese patent laid-open No. 6-332152 Disclosure of Invention Technical problem to be solved by the invention As a phase shift mask used in the manufacture of high definition (600 ppi or more) panels in recent years, in order to be able to transfer a high definition pattern, a fine phase shift film pattern having an aperture of 6 μm or less and a line width of 4 μm or less is required to be formed on the phase shift mask. Specifically, a phase shift mask having a fine phase shift film pattern with an aperture of 1.5 μm is required. In order to achieve higher definition pattern transfer, a phase shift mask base plate having a phase shift film with high transmittance of 30% or more with respect to exposure light and a phase shift mask having a phase shift film pattern with transmittance of 30% or more with respect to exposure light are required. Moreover, it is not easy to stabilize the film forming conditions of such a phase shift film, and fluctuation (variation) is likely to occur in the film thickness of the phase shift film to be formed. When a fine pattern is formed on a phase shift mask base plate provided with such a phase shift film to manufacture a phase shift mask, a cleaning process and an etching process are performed. In addition, in the manufactured phase shift mask, a cleaning process is appropriately performed at the time of use. For these reasons, in the phase shift mask, the film thickness of the phase shift film formed with the pattern is reduced. Further, there are cases where the transmittance of the phase shift film greatly fluctuates due to fluctuation in the film thickness of such a phase shift film (including a patterned phase shift film, hereinafter the same), and it is known that the desired transfer characteristics are affected. The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a phase shift mask base plate, a phase shift mask, a method for manufacturing a phase shift mask, and a method for manufacturing a display device, which can suppress fluctuation in transmittance with respect to a representative wavelength of exposure light and have a desirably high transmittance even when fluctuation in film thickness occurs in a phase shift film, and can perform good pattern transfer. Technical scheme for solving technical problems The present invention has been made to solve the above-mentioned problems, and has the following aspects. (Scheme 1) A phase shift mask base plate having a phase shift film on a transparent substrate, characterized in that, The phase shift film has a transmittance of 30% to 80% at a representative wavelength of an exposure wavelength, an attenuation coefficient k of 0.10 to 0.25, a refractive index n of 2.20 to 2.57, The representative wavelength of the exposure wavelength is in the range of 313-436 nm, The representative wavelength is located between a valley of the surface reflectivity of the adjacent short wavelength side and a peak of the surface reflectivity of the adjacent long wavelength side i