CN110967918B - Phase shift mask, manufacturing method thereof and phase shift mask photoetching equipment - Google Patents
Phase shift mask, manufacturing method thereof and phase shift mask photoetching equipment Download PDFInfo
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- CN110967918B CN110967918B CN201811139617.6A CN201811139617A CN110967918B CN 110967918 B CN110967918 B CN 110967918B CN 201811139617 A CN201811139617 A CN 201811139617A CN 110967918 B CN110967918 B CN 110967918B
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- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F1/00—Originals for photomechanical production of textured or patterned surfaces, e.g., masks, photo-masks, reticles; Mask blanks or pellicles therefor; Containers specially adapted therefor; Preparation thereof
- G03F1/26—Phase shift masks [PSM]; PSM blanks; Preparation thereof
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Abstract
The invention provides a phase shift mask, a manufacturing method thereof and phase shift mask photoetching equipment, wherein the phase shift mask comprises a transparent photoetching plate substrate; the upper surface of the transparent photoetching plate substrate comprises first and second light-transmitting areas which extend along a preset direction and are alternately arranged; the first light-transmitting region comprises first and second phase-shifting regions which are alternately arranged at intervals in sequence along a preset direction, and the second light-transmitting region comprises fourth and third phase-shifting regions which are alternately arranged at intervals in sequence along the preset direction; the lower surface of the reticle substrate includes a plurality of opaque pattern regions extending in a predetermined direction, which simultaneously partially shield the first and second phase shift regions and the fourth and third phase shift regions. The outgoing light beams passing through the first phase shift area, the second phase shift area, the third phase shift area and the fourth phase shift area have phase differences of 90 degrees, 180 degrees and 270 degrees respectively, so that the dark area pattern formed on the surface of the wafer is a complete dark area, and the image resolution of the photoetching pattern on the surface of the wafer is improved.
Description
Technical Field
The invention relates to the technical field of semiconductor integrated circuit manufacturing, in particular to a phase shift mask for preparing a columnar structure and a manufacturing method thereof, and further relates to phase shift mask photoetching equipment.
Background
With the continued development of large scale integrated circuit technology, equipment and products, ever higher lithographic resolution is required, with larger chip and silicon die sizes. The basic idea of the lithography technique is that the light intensity on the wafer surface is determined by the combination of waves diffracted by the individual light-transmitting holes.
The phase shift mask technique (PhaseShiftMask, PSM) can improve the resolution by generating 180-degree phase difference between the light beams passing through adjacent light transmission areas of mask patterns on a mask plate, namely the light beams without a phase shift layer area and the light beams passing through the phase shift layer area, so that the light intensity of dark areas on the surface of a silicon wafer is weakened due to destructive interference, the multiplication resolution under the same optical system is improved, and the edge steepness and the exposure tolerance are improved. The phase shift mask is various in variety and functions. The most common are alternating phase shift masks, chromeless phase shift masks, edge phase shift masks, auxiliary phase shift masks, attenuated phase shift masks (att PSM), etc.
An attenuated phase shift mask, which is a completely opaque portion of a conventional chrome mask, is replaced with chrome oxide or the like that is partially transparent and imparts a certain phase shift. One of the methods is to adopt a double-layer structure to achieve the purpose, and the other method adopts a single-layer structure, namely, adopts a single-layer film material such as CrO, crON or MoSi as an attenuation layer and a phase shifter material, controls the layer thickness according to the refractive index of the attenuation layer and the phase shifter material, so that 180-degree phase shift is achieved, and meanwhile, the purpose of attenuating light intensity with a certain transmittance is achieved. Fig. 1 is a schematic diagram of an attenuated phase shift mask (att PSM) used in the fabrication of a pillar structure according to the prior art, and fig. 2 is a schematic diagram of a method for fabricating an attenuated phase shift mask (att PSM) according to the prior art. As shown in fig. 1, the mask includes a substrate 110 and a light shielding film 111 formed thereon, wherein the substrate 110 may be made of a light transmissive material such as quartz glass, and the light shielding film 111 may be made of a material such as CrO, crON, or MoSi. As shown in fig. 2, the method for preparing the mask includes the following steps: a) A MoSi layer 120, a Cr layer 130, and a photoresist PR layer 140 are sequentially formed on a substrate 110 such as quartz glass; b) Forming a patterned photoresist PR layer 141; c) Etching, namely etching the Cr layer 130 and the MoSi layer 120 by taking the patterned photoresist PR layer 141 as a mask to obtain a patterned Cr layer 131 and a patterned MoSi layer 121 until the substrate 110 is etched; d) Removing the patterned photoresist PR layer 141; e) Removal of patterned Cr layer 131 results in an attenuated phase shift mask comprising substrate 110 and patterned MoSi layer 121. However, when the attenuated phase shift mask is used to fabricate the columnar structure, a secondary light intensity distribution (as shown in fig. 1) occurs in a dark region corresponding to the light shielding film 121 due to a coherent effect, so that the height and shape of the columnar structure cannot be expected.
Therefore, how to improve the uniform distribution of the photolithography patterns when preparing the columnar structures on the surface of the silicon wafer, and form complete dark areas on the surface of the wafer corresponding to the opaque areas, so as to improve the resolution of the images is a technical problem which needs to be solved by those skilled in the art.
Disclosure of Invention
The present invention provides a phase shift mask for fabricating a pillar structure, a phase shift mask lithographic apparatus for fabricating a pillar structure, and a method of fabricating a phase shift mask for fabricating a pillar structure, to overcome or alleviate one or more of the problems of the prior art, and to provide at least one advantageous option.
As one aspect of the present invention, there is provided a phase shift mask for preparing a columnar structure, comprising:
a transparent photolithographic plate substrate;
the upper surface of the transparent photoetching plate substrate comprises a plurality of first light transmission areas and second light transmission areas which extend along a preset direction, and the first light transmission areas and the second light transmission areas are alternately arranged; each first light transmission region comprises a first phase shift region and a second phase shift region which are alternately arranged at intervals in sequence along the preset direction, and each second light transmission region comprises a fourth phase shift region and a third phase shift region which are alternately arranged at intervals in sequence along the preset direction;
the lower surface of the photoetching plate substrate comprises a plurality of opaque pattern areas extending along the preset direction, and each opaque pattern area simultaneously partially shields the first phase shifting area and the second phase shifting area in each first light transmission area and simultaneously partially shields the fourth phase shifting area and the third phase shifting area in each second light transmission area;
the phase difference between the outgoing light beam passing through the first phase shift region and the outgoing light beam passing through the second phase shift region is 90 degrees, the phase difference between the outgoing light beam passing through the first phase shift region and the outgoing light beam passing through the third phase shift region is 180 degrees, and the phase difference between the outgoing light beam passing through the first phase shift region and the outgoing light beam passing through the fourth phase shift region is 270 degrees.
Preferably, in the phase shift mask, the first phase shift region has a first thickness, the second phase shift region has a second thickness, the third phase shift region has a third thickness, the fourth phase shift region has a fourth thickness, the first thickness is greater than the second thickness, the second thickness is greater than the third thickness, the third thickness is greater than the fourth thickness, and the first thickness is equal to the thickness of the transparent mask substrate.
Preferably, in the phase shift mask, a thickness difference H1 exists between the first thickness and the second thickness, a thickness difference H2 exists between the first thickness and the third thickness, a thickness difference H3 exists between the first thickness and the fourth thickness, and the thickness difference H1: h2: h3 =1/2: 1:3/2.
Preferably, in the phase shift mask, the opaque pattern region is constituted by a light shielding film.
Preferably, in the phase shift mask, the light shielding film includes a chromium film.
The invention also provides a phase shift mask lithography apparatus for preparing a columnar structure, comprising:
a phase shift reticle as described above;
and the exposure device is used for exposing the photoresist on the surface of the wafer by using the phase-shift mask.
The invention also provides a manufacturing method of the phase shift mask for preparing the columnar structure, which comprises the following steps:
providing a transparent photoetching plate substrate;
sequentially forming a shading film and patterned photoresist on the upper surface of the transparent photoetching plate substrate, wherein the shading film comprises a light-proof material;
patterning the light shielding film according to the patterned photoresist, forming a plurality of opaque regions covered by the light shielding film and a plurality of transparent regions uncovered by the light shielding film on the transparent photoetching plate substrate, wherein the opaque regions and the transparent regions are alternately distributed;
removing the photoresist, and treating the upper surfaces of the light-transmitting areas by taking the patterned shading film as a mask to form the light-transmitting areas into a plurality of first light-transmitting areas and second light-transmitting areas which extend along a preset direction, wherein the first light-transmitting areas and the second light-transmitting areas are alternately arranged; each first light-transmitting region comprises a first phase shifting region and a second phase shifting region which are alternately arranged at intervals in sequence along a first direction, and each second light-transmitting region comprises a fourth phase shifting region and a third phase shifting region which are alternately arranged at intervals in sequence along the first direction;
forming a plurality of opaque pattern regions extending in the predetermined direction on a lower surface of the transparent photolithographic board substrate, each of the opaque pattern regions simultaneously partially shielding the first phase shift region and the second phase shift region in each of the first light transmission regions and simultaneously partially shielding the fourth phase shift region and the third phase shift region in each of the second light transmission regions;
the phase difference between the outgoing light beam passing through the first phase shift region and the outgoing light beam passing through the second phase shift region is 90 degrees, the phase difference between the outgoing light beam passing through the first phase shift region and the outgoing light beam passing through the third phase shift region is 180 degrees, and the phase difference between the outgoing light beam of the first phase shift region and the outgoing light beam passing through the fourth phase shift region is 270 degrees.
Preferably, in the above method, the first phase shift region has a first thickness, the second phase shift region has a second thickness, the third phase shift region has a third thickness, the fourth phase shift region has a fourth thickness, the first thickness is greater than the second thickness, the second thickness is greater than the third thickness, the third thickness is greater than the fourth thickness, and the first thickness is equal to the thickness of the transparent lithographic plate substrate.
Preferably, in the above method, a thickness difference H1 exists between the first thickness and the second thickness, a thickness difference H2 exists between the first thickness and the third thickness, a thickness difference H3 exists between the first thickness and the fourth thickness, and the thickness difference H1: h2: h3 =1/2: 1:3/2.
Preferably, the method further comprises the step of removing the light shielding film before forming the plurality of the light-opaque pattern regions.
The invention adopts the technical scheme and has the following advantages:
in the scheme, the phase shift mask is provided, and compared with the prior art, the phase shift mask forms four phases of emergent light beams. The phase shift mask comprises a transparent photoetching plate substrate, wherein the upper surface of the transparent photoetching plate substrate comprises a plurality of first light transmission areas and second light transmission areas which extend along a preset direction, and the first light transmission areas and the second light transmission areas are alternately arranged; each first light transmitting region comprises a first phase shifting region and a second phase shifting region which are alternately arranged at intervals in sequence along the preset direction, and each second light transmitting region comprises a fourth phase shifting region and a third phase shifting region which are alternately arranged at intervals in sequence along the preset direction. The lower surface of the transparent photolithography plate substrate includes a plurality of opaque pattern regions extending in the predetermined direction, each of the opaque pattern regions partially shielding the first phase shift region and the second phase shift region in each of the first light transmission regions at the same time, and partially shielding the fourth phase shift region and the third phase shift region in each of the second light transmission regions at the same time. And the phase difference between the first emergent light beam passing through the first phase shift region, the second emergent light beam passing through the second phase shift region, the third emergent light beam passing through the third phase shift region and the fourth emergent light beam of the fourth phase shift region is 90 degrees in sequence, so that a dark region pattern formed on the surface of the wafer is a complete dark region, and the image resolution of the photoetching pattern on the surface of the wafer is improved.
The foregoing summary is for the purpose of the specification only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features of the present invention will become apparent by reference to the drawings and the following detailed description.
Drawings
The features and advantages of the present invention will be more clearly understood by reference to the accompanying drawings, which are illustrative and should not be construed as limiting the invention in any way, in which:
fig. 1 is a schematic diagram of an attenuated phase shift mask (att PSM) for fabricating columnar structures according to the prior art.
Fig. 2 is a schematic diagram of a prior art method of fabricating an attenuated phase shift mask (att PSM).
Fig. 3 is a schematic diagram of a phase shift mask according to the present invention.
FIG. 4 is a schematic diagram of the beam propagation waveform of the phase shift mask of the present invention.
Fig. 5 is a schematic view of a light transmission region of a phase shift mask for preparing a columnar structure according to an embodiment of the present invention.
Fig. 6-1 and 6-2 are schematic diagrams of a phase shift mask for preparing a columnar structure according to a second embodiment of the present invention.
Fig. 7 is a flowchart of a method for preparing a phase shift mask for preparing a columnar structure according to a third embodiment of the present invention.
FIGS. 7-1 to 7-5 are schematic diagrams of structures obtained at various steps in the method of FIG. 7.
Fig. 8 is a schematic diagram of a phase shift mask lithography apparatus for preparing a columnar structure according to a fourth embodiment of the present invention.
Reference numerals
110. Substrate board
111. Light shielding film
120 MoSi layer
130 Cr layer
140. Photoresist PR layer
141. Patterned photoresist PR layer
131. Patterned Cr layer
121. Patterned MoSi layer
210. Transparent photoetching plate substrate
220. Light shielding film
221. Patterned light shielding film
230. Photoresist
231. Patterned photoresist
241. First part
242. Second part
310. Substrate board
320. Light shielding film
330. A first light-transmitting region
340. Second light-transmitting region
41. Glass substrate
42. Air-conditioner
410. First light ray
420. Second light ray
510. Substrate board
530. First phase shift region
531. Second phase shift region
532. Third phase shift region
533. Fourth phase shift region
610. Lithographic apparatus and substrate
630. First phase shift region
631. Second phase shift region
632. Third phase shift region
633. Fourth phase shift region
640. Opaque pattern area
810. Exposure apparatus
820. Phase shift mask
830. Wafer with a plurality of wafers
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to fall within the scope of the invention.
The present invention provides a phase shift mask for preparing a columnar structure, and fig. 3 is a schematic diagram of the phase shift mask in the present invention, which includes a substrate 310 and a light shielding film 320 formed thereon, wherein the substrate 310 includes quartz glass, etc., and the light shielding film 320 includes an opaque material, preferably a chrome film, and of course, may include a compound such as chrome molybdenum (MoCr) or one or more selected from oxygen (O), nitrogen (N) and carbon (C), for example, moCrO, moCrN, moCrC, moCrCN, moCrCO, moCrCON, crO, crN, crC, crCN, crCO and CrCON, etc. A first light-transmitting region 330 and a second light-transmitting region 340 which are not covered by the light-shielding film 320 are formed on the substrate 310, and the substrate 310 is further etched in the second light-transmitting region 340 such that the phases of light emitted from the first light-transmitting region 330 and the second light-transmitting region 340 are 180 degrees out of phase.
For a substrate 310 having a refractive index n, the phase shift angle θ is calculated as follows:
the following formula can be obtained:
wherein a is the difference between the thickness of the substrate corresponding to the first light-transmitting region 330 and the thickness of the substrate corresponding to the second light-transmitting region 340, i.e. the etching depth; lambda is the wavelength of the incident light.
For a lithographic apparatus employing an ArF excimer laser as the light source, the exit wavelength of the light source comprises 193nm, i.e. the wavelength of the first incident light beam passing through the first light transmissive region 330 and the second incident light beam passing through the second light transmissive region 340 comprises 193nm; as can be seen from the above calculation formula, in order to obtain the 180 degree phase shift, the difference between the substrate thickness corresponding to the first light transmitting region 330 and the substrate thickness corresponding to the second light transmitting region 340 includes 172nm. When light sources with other wavelengths are used, corresponding calculations can be made according to the above formula as well.
As shown in fig. 4, since the propagation speed of light in air and the propagation speed in the glass substrate are different, a certain phase difference occurs when light propagates the same distance in the glass substrate 41 and the air 42; by properly adjusting the propagation distance of light in air, the phase difference between the first light ray 410 emitted from the lower surface of the glass substrate and the second light ray 420 emitted from the phase shift region on the plane of the lower surface of the glass substrate is 180 degrees, so that the amplitudes of the first light ray and the second light ray are overlapped to be 0, the diffraction effect is reduced, and a complete dark region is formed in the region corresponding to the opaque region.
Example 1
The present invention provides a phase shift reticle for fabricating columnar structures, which in one particular embodiment, as schematically illustrated in fig. 5, includes a substrate 510, the substrate 510 including a quartz glass or other light transmissive reticle substrate. A first phase shift region 530 having a first thickness L1, a second phase shift region 531 having a second thickness L2, a third phase shift region 532 having a third thickness L3, and a fourth phase shift region 533 having a fourth thickness L4 are formed on the substrate 510, the first outgoing light beam transmitted through the first phase shift region 530 and the second outgoing light beam transmitted through the second phase shift region 531 having a phase difference of 90 degrees, and the first outgoing light beam transmitted through the first phase shift region 530 and the third outgoing light beam transmitted through the third phase shift region 532 having a phase difference of 180 degrees, and the first outgoing light beam transmitted through the first phase shift region 530 and the fourth outgoing light beam transmitted through the fourth phase shift region 533 having a phase difference of 270 degrees. Specifically, the first phase shift region 530 may be referred to as a 0 degree phase region, the second phase shift region 531 may be referred to as a 90 degree phase region, the third phase shift region 532 may be referred to as a 180 degree phase region, and the fourth phase shift region 533 may be referred to as a 270 degree phase region. A groove having three etching depths, where L1> L2> L3> L4, and the first thickness L1 is equal to the thickness of the light-transmitting substrate, may be formed on the substrate 510.
Wherein the exit wavelength of the light source comprises 193nm, i.e. the wavelengths of the first to fourth exit light beams comprise 193nm. The first thickness L1 and the second thickness L2 have a thickness difference H1, the first thickness L1 and the third thickness L3 have a thickness difference H2, the first thickness L1 and the fourth thickness L4 have a thickness difference H3, the H1: h2: h3 =1/2: 1:3/2, wherein the range of H2 comprises 172nm.
Preferably, in the phase shift mask, the first phase shift region 530, the second phase shift region 531, the third phase shift region 532 and the fourth phase shift region 533 have the same width.
When the mask plate manufactured by adopting the structure is used for manufacturing a columnar structure, the existence of light intensity distribution in a dark area can be avoided, so that a complete dark area can be obtained.
Example two
The present invention provides a phase shift mask for fabricating columnar structures, in one particular embodiment, as shown in fig. 6-1, the mask includes a lithographic plate substrate 610, the lithographic plate substrate 610 comprising quartz glass or other transparent lithographic plate substrate. The upper surface of the photolithographic plate substrate 610 includes a plurality of first light-transmitting regions and second light-transmitting regions extending in a predetermined direction, which may be a horizontal direction, as shown in fig. 6-1. Each of the first light-transmitting regions and the second light-transmitting regions is alternately arranged on the photolithographic board substrate 610; each of the first light transmitting regions includes a first phase shifting region 630 having a first thickness L1 and a second phase shifting region 631 having a second thickness L2 which are alternately arranged in sequence at intervals in a horizontal direction, each of the second light transmitting regions includes a fourth phase shifting region 633 having a fourth thickness L4 and a third phase shifting region 632 having a third thickness L3 which are alternately arranged in sequence at intervals in the horizontal direction, a phase difference of 90 degrees is provided between the first outgoing light beam transmitted through the first phase shifting region 630 and the second outgoing light beam transmitted through the second phase shifting region 631, a phase difference of 180 degrees is provided between the first outgoing light beam transmitted through the first phase shifting region 630 and the third outgoing light beam transmitted through the third phase shifting region 632, and a phase difference of 270 degrees is provided between the first outgoing light beam transmitted through the first phase shifting region 630 and the fourth outgoing light beam transmitted through the fourth phase shifting region 633. Specifically, the first phase shift region 630 may be referred to as a 0 degree phase region, the second phase shift region 631 may be referred to as a 90 degree phase region, the third phase shift region 632 may be referred to as a 180 degree phase region, and the fourth phase shift region 633 may be referred to as a 270 degree phase region.
Specifically, the first phase shift region 630, the second phase shift region 631, the third phase shift region 632, and the fourth phase shift region 633 are diamond, rectangular, or square of the same size. In a preferred embodiment of the present embodiment shown in fig. 6-1, the first phase shift region 630, the second phase shift region 631, the third phase shift region 632 and the fourth phase shift region 633 are square shapes of the same size, the first phase shift region 630, the second phase shift region 631, the third phase shift region 632 and the fourth phase shift region 633 constitute one large square shape, and the first phase shift region 630, the second phase shift region 631, the third phase shift region 632 and the fourth phase shift region 633 are located in the upper left corner, the upper right corner, the lower right corner and the lower left corner of the large square shape in this order. It should be appreciated that the locations of the first phase shift region 630, the second phase shift region 631, the third phase shift region 632, and the fourth phase shift region 633 in the square they constitute may vary as long as it is satisfied that the first phase shift region 630, the second phase shift region 631, the third phase shift region 632, and the fourth phase shift region 633 are sequentially connected in order. Grooves having three different etching depths may be formed on the photolithographic board substrate 610 to form the second, third and fourth phase shift regions 631, 632 and 633, respectively, wherein L1> L2> L3> L4, and the first thickness L1 of the first phase shift region 630 is equal to the thickness of the photolithographic board substrate 610, and L1, L2, L3, L4 are sequentially different by a predetermined thickness.
Wherein the exit wavelength of the light source comprises 193nm, i.e. the wavelengths of the first to fourth exit light beams comprise 193nm. The first thickness L1 and the second thickness L2 have a thickness difference H1, the first thickness L1 and the third thickness L3 have a thickness difference H2, the first thickness L1 and the fourth thickness L4 have a thickness difference H3, the H1: h2: h3 =1/2: 1:3/2, wherein the range of H2 comprises 172nm.
As shown in fig. 6-2, after the formation of the photolithographic board substrate 610, an opaque pattern region 640 may be formed on the lower surface of the photolithographic board substrate 610, the opaque pattern region 640 being formed at a region corresponding to a region interfacing the first phase shift region 630, the second phase shift region 631, the third phase shift region 632 and the fourth phase shift region 633. Specifically, as shown in fig. 6-2, each of the opaque pattern regions 640 partially shields the first phase shift region 630 and the second phase shift region 631 in each of the first light transmission regions at the same time, and partially shields the fourth phase shift region 633 and the third phase shift region 632 in each of the second light transmission regions at the same time. The pattern of the light-opaque pattern region 640 may include a circular shape, a rectangular shape, or the like; the pattern of the opaque pattern region 640 may have other shapes depending on the desired columnar structure to be produced. The light-opaque pattern region may be formed of a light-shielding film including an opaque material, preferably a chrome film, and of course, may further include a compound such as chrome molybdenum (MoCr) or one or more selected from oxygen (O), nitrogen (N), and carbon (C), for example, moCrO, moCrN, moCrC, moCrCN, moCrCO, moCrCON, crO, crN, crC, crCN, crCO, crCON, and the like.
In the phase shift mask, the first phase shift region 630, the second phase shift region 631, the third phase shift region 632 and the fourth phase shift region 633 have the same width.
When the mask plate manufactured by adopting the structure is used for manufacturing a columnar structure, the existence of light intensity distribution in a dark area can be avoided, so that a complete dark area is obtained, and the resolution is improved.
Example III
The invention provides a manufacturing method of a phase shift mask for preparing a columnar structure, as shown in figures 7-1 to 7-5, comprising the following steps:
a) As shown in fig. 7-1, a transparent photolithography plate substrate 210 is provided, and a light shielding film 220 and a photoresist 230 are sequentially formed on the transparent photolithography plate substrate 210, the light shielding film 220 including an opaque material.
The opaque material is preferably a chromium film. Of course, it is also possible to include such compounds as chrome molybdenum (MoCr) or one or more selected from oxygen (O), nitrogen (N) and carbon (C), for example, moCrO, moCrN, moCrC, moCrCN, moCrCO, moCrCON, crO, crN, crC, crCN, crCO and CrCON, etc.
b) As shown in fig. 7-2, the photoresist 230 is exposed and developed to form a patterned photoresist 231 to ensure that the light shielding film 220 is etched according to the exposure pattern.
c) As shown in fig. 7-3 and 7-4, the light shielding film 220 is etched along the patterned photoresist 231; after etching, a patterned light shielding film 221 is formed, and the surface of the transparent photoetching plate substrate 210 is exposed, so that a light-transmitting area which is not covered by the pattern is formed.
d) As shown in fig. 7 to 5, after the patterned photoresist 231 is removed, a light-transmitting region is formed in the middle of the light-opaque region corresponding to the light-shielding film 221.
e) The light-transmitting area is divided into at least two portions, and a first portion 241 having a first thickness and a second portion 242 having a second thickness are formed, wherein a light beam transmitted through the first portion 241 and a light beam transmitted through the second portion 242 have a phase difference of a predetermined angle therebetween.
In the above step, the first portion 241 is not etched, i.e., it has the same thickness as the transparent reticle substrate 210. The method of forming the second portion 242 having the second thickness may include: forming a photoresist and a light shielding film on the surface of the light transmitting region, wherein the light shielding film covers the surface of the substrate corresponding to the first portion 241; etching the light-transmitting region with the photoresist formed on the surface to form a second part 242 with a second thickness; wherein, a preset thickness difference is formed between the substrate thickness of the first portion 241 and the substrate thickness of the second portion 242, so that a predetermined angle phase difference is formed between the light beam transmitted through the first portion 241 and the light beam transmitted through the second portion 242.
The plurality of portions having different thicknesses may be designed according to actual needs, for example, in a preferred embodiment of the present embodiment, a phase shift mask having four phases of 0 degrees, 90 degrees, 180 degrees and 270 degrees is formed, and in the method for manufacturing a phase shift mask, the step e) may include the steps of:
removing the photoresist, and processing the upper surface of the light-transmitting area to form a plurality of first light-transmitting areas and second light-transmitting areas extending along a preset direction on the upper surface of the transparent photoetching plate substrate, wherein the first light-transmitting areas and the second light-transmitting areas are alternately arranged; wherein each first light-transmitting region includes a first phase shift region and a second phase shift region alternately arranged at intervals in sequence along the predetermined direction, and each second light-transmitting region includes a fourth phase shift region and a third phase shift region alternately arranged at intervals in sequence along the predetermined direction;
forming a plurality of opaque pattern regions extending in a predetermined direction on a lower surface of the transparent photolithographic board substrate, each of the opaque pattern regions simultaneously partially shielding the first phase shift region and the second phase shift region in each of the first light transmission regions and simultaneously partially shielding the fourth phase shift region and the third phase shift region in each of the second light transmission regions;
the phase difference between the outgoing light beam passing through the first phase shift region and the outgoing light beam passing through the second phase shift region is 90 degrees, the phase difference between the outgoing light beam passing through the first phase shift region and the outgoing light beam passing through the third phase shift region is 180 degrees, and the phase difference between the outgoing light beam of the first phase shift region and the outgoing light beam passing through the fourth phase shift region is 270 degrees.
In the above method, the first phase shift region has a first thickness, the second phase shift region has a second thickness, the third phase shift region has a third thickness, the fourth phase shift region has a fourth thickness, the first thickness is greater than the second thickness, the second thickness is greater than the third thickness, the third thickness is greater than the fourth thickness, and the first thickness is equal to the thickness of the transparent photolithography plate substrate.
In the above method, a thickness difference H1 exists between the first thickness and the second thickness, a thickness difference H2 exists between the first thickness and the third thickness, a thickness difference H3 exists between the first thickness and the fourth thickness, and the thickness difference H1: h2: h3 =1/2: 1:3/2.
In the above method, the light-impermeable pattern area is constituted by a light-shielding film.
In the above method, a dark region pattern on the wafer surface under the phase shift mask is aligned with the opaque region, and the corrected dark region pattern has substantially the same size as the opaque region.
When the mask plate manufactured by the method is used for manufacturing the columnar structure, the light intensity distribution in the dark area can be avoided, so that the complete dark area is obtained.
Example IV
The present invention also provides a phase shift mask lithography apparatus for preparing a columnar structure, as shown in fig. 8, the schematic diagram of the phase shift mask lithography apparatus for preparing a columnar structure includes:
the phase shift mask 820 described in embodiment one or embodiment two;
an exposure device 810 located above the phase shift mask 820 for generating incident light; and
a wafer 830 disposed below the phase shift mask 820;
the phase shift mask 820 includes a transparent mask substrate, and a plurality of first light-transmitting regions and second light-transmitting regions extending along a predetermined direction are formed on an upper surface of the transparent mask substrate, and each of the first light-transmitting regions and the second light-transmitting regions are alternately arranged; each first light-transmitting region comprises a first phase shift region and a second phase shift region which are alternately arranged at intervals in sequence along the preset direction, each second light-transmitting region comprises a fourth phase shift region and a third phase shift region which are alternately arranged at intervals in sequence along the preset direction, wherein a phase difference of 90 degrees is formed between an outgoing light beam penetrating through the first phase shift region and an outgoing light beam penetrating through the second phase shift region, a phase difference of 180 degrees is formed between an outgoing light beam penetrating through the first phase shift region and an outgoing light beam penetrating through the third phase shift region, and a phase difference of 270 degrees is formed between an outgoing light beam of the first phase shift region and an outgoing light beam penetrating through the fourth phase shift region; the other surface of the photoetching plate substrate is provided with a plurality of opaque pattern areas extending along a first direction, and each opaque pattern area simultaneously partially shields the first phase shift area and the second phase shift area in each first light transmission area and simultaneously partially shields the fourth phase shift area and the third phase shift area in each second light transmission area;
the incident light generated by the exposure device passes through the first phase shift region on the phase shift mask plate to form first emergent light, the incident light passes through the second phase shift region to form second emergent light, the incident light passes through the third phase shift region to form third emergent light, and the incident light passes through the fourth phase shift region to form fourth emergent light; the first emergent light and the second emergent light have a phase difference of 90 degrees, the first emergent light and the third emergent light have a phase difference of 180 degrees, and the first emergent light and the fourth emergent light have a phase difference of 270 degrees.
The pattern of the opaque region includes circular, rectangular, etc.; the pattern of opaque regions may have other shapes depending on the columnar structure desired to be produced.
The above-described embodiments illustrate only the principle of the invention and its efficacy, but are not intended to limit the invention, as various modifications and variations can be made by those skilled in the art without departing from the spirit and scope of the invention, which is defined in the appended claims.
Claims (10)
1. A phase shift mask for fabricating a columnar structure, comprising:
a transparent photolithographic plate substrate;
the upper surface of the transparent photoetching plate substrate comprises a plurality of first light transmission areas and second light transmission areas which extend along a preset direction, and the first light transmission areas and the second light transmission areas are alternately arranged; each first light transmission region comprises a first phase shift region and a second phase shift region which are alternately arranged at intervals in sequence along the preset direction, and each second light transmission region comprises a fourth phase shift region and a third phase shift region which are alternately arranged at intervals in sequence along the preset direction;
the lower surface of the transparent photoetching plate substrate comprises a plurality of opaque pattern areas extending along the preset direction, and each opaque pattern area simultaneously partially shields the first phase shifting area and the second phase shifting area in each first light transmission area and simultaneously partially shields the fourth phase shifting area and the third phase shifting area in each second light transmission area;
the phase difference between the outgoing light beam passing through the first phase shift region and the outgoing light beam passing through the second phase shift region is 90 degrees, the phase difference between the outgoing light beam passing through the first phase shift region and the outgoing light beam passing through the third phase shift region is 180 degrees, and the phase difference between the outgoing light beam passing through the first phase shift region and the outgoing light beam passing through the fourth phase shift region is 270 degrees.
2. The phase shift mask of claim 1, wherein the first phase shift region has a first thickness, the second phase shift region has a second thickness, the third phase shift region has a third thickness, the fourth phase shift region has a fourth thickness, the first thickness is greater than the second thickness, the second thickness is greater than the third thickness, the third thickness is greater than the fourth thickness, and the first thickness is equal to the thickness of the transparent reticle substrate.
3. The phase shift reticle of claim 2, wherein the first thickness has a thickness difference H1 from the second thickness, the first thickness has a thickness difference H2 from the third thickness, the first thickness has a thickness difference H3 from the fourth thickness, the H1: h2: h3 =1/2: 1:3/2.
4. The phase shift mask of claim 1, wherein the opaque pattern region is comprised of a light shielding film.
5. The phase shift mask of claim 4, wherein the light shielding film comprises a chromium film.
6. A phase shift mask lithographic apparatus for producing a columnar structure, comprising:
the phase shift mask of any one of claims 1-5;
and the exposure device is used for exposing the photoresist on the surface of the wafer by using the phase-shift mask.
7. The manufacturing method of the phase shift mask for preparing the columnar structure is characterized by comprising the following steps of:
providing a transparent photoetching plate substrate;
sequentially forming a shading film and patterned photoresist on the upper surface of the transparent photoetching plate substrate, wherein the shading film comprises a light-proof material;
patterning the light shielding film according to the patterned photoresist, forming a plurality of opaque regions covered by the light shielding film and a plurality of transparent regions uncovered by the light shielding film on the transparent photoetching plate substrate, wherein the opaque regions and the transparent regions are alternately distributed;
removing the photoresist, and processing the upper surfaces of the light-transmitting areas to form a plurality of first light-transmitting areas and second light-transmitting areas extending along a preset direction on the upper surface of the transparent photoetching plate substrate, wherein the first light-transmitting areas and the second light-transmitting areas are alternately arranged; each first light-transmitting region comprises a first phase shifting region and a second phase shifting region which are alternately arranged at intervals in sequence along a first direction, and each second light-transmitting region comprises a fourth phase shifting region and a third phase shifting region which are alternately arranged at intervals in sequence along the first direction;
forming a plurality of opaque pattern regions extending in the predetermined direction on a lower surface of the transparent photolithographic board substrate, each of the opaque pattern regions simultaneously partially shielding the first phase shift region and the second phase shift region in each of the first light transmission regions and simultaneously partially shielding the fourth phase shift region and the third phase shift region in each of the second light transmission regions;
the phase difference between the outgoing light beam passing through the first phase shift region and the outgoing light beam passing through the second phase shift region is 90 degrees, the phase difference between the outgoing light beam passing through the first phase shift region and the outgoing light beam passing through the third phase shift region is 180 degrees, and the phase difference between the outgoing light beam of the first phase shift region and the outgoing light beam passing through the fourth phase shift region is 270 degrees.
8. The method of claim 7, wherein the first phase shift region has a first thickness, the second phase shift region has a second thickness, the third phase shift region has a third thickness, the fourth phase shift region has a fourth thickness, the first thickness is greater than the second thickness, the second thickness is greater than the third thickness, the third thickness is greater than the fourth thickness, and the first thickness is equal to the thickness of the transparent reticle substrate.
9. The method of claim 8, wherein the first thickness has a thickness difference H1 from the second thickness, the first thickness has a thickness difference H2 from the third thickness, the first thickness has a thickness difference H3 from the fourth thickness, the H1: h2: h3 =1/2: 1:3/2.
10. The method according to any one of claims 7 to 9, wherein before forming a plurality of the light-opaque pattern regions, the method further comprises the step of removing the light-shielding film.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN1469431A (en) * | 2002-06-12 | 2004-01-21 | ���ǵ�����ʽ���� | Method for producing alternating phase-shift mask |
| TW200500512A (en) * | 2002-12-04 | 2005-01-01 | Adv Lcd Tech Dev Ct Co Ltd | Crystallization apparatus and crystallization method |
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| US6605396B2 (en) * | 2001-08-06 | 2003-08-12 | Infineon Technologies, Ag | Resolution enhancement for alternating phase shift masks |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1469431A (en) * | 2002-06-12 | 2004-01-21 | ���ǵ�����ʽ���� | Method for producing alternating phase-shift mask |
| TW200500512A (en) * | 2002-12-04 | 2005-01-01 | Adv Lcd Tech Dev Ct Co Ltd | Crystallization apparatus and crystallization method |
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