TW202209424A - Mask and preparation method thereof - Google Patents

Abstract

The invention provides a mask plate and a preparation method thereof. Firstly, a bottom die with a groove is provided, then a light-proof layer is formed in the groove, then a light-transmitting transition layer is formed on the bottom die and covered with a light-transmitting substrate, and the light-transmitting transition layer can serve as a bonding layer between the light-transmitting substrate and the light-proof layer so that the mask plate can be formed after the bottom die is demoulded and demoulded. The light-proof layer protrudes out of the light-transmitting substrate, and when the mask is used for exposing the substrate with the pits, the light-proof layer can extend into the pits of the substrate, so that the distance between the light-proof layer and the bottoms of the pits is reduced, the sharpness and clarity of the edges of the patterns formed after exposure are improved, and the precision and reliability of the device are further improved.

Description

Mask plate and preparation method thereof

The present invention relates to the technical field of lens preparation, in particular to a mask plate and a preparation method thereof.

Exposure technology can be divided into proximity exposure, contact exposure and non-proximity exposure. The difference between the three exposure methods lies in whether the relative relationship between the mask plate and the substrate is close, close or separate during exposure. Proximity exposure and contact exposure have the characteristics of high resolution, large copy area, good copy accuracy, simple exposure equipment, convenient operation and high production efficiency. It will generate electrostatic adsorption of dust and other particles. Each contact or approach process will cause certain defects on the substrate and the mask version, which will affect the yield and the life of the mask version, and the improvement of alignment accuracy will also be greatly affected. limits. Therefore, proximity exposure and contact exposure are generally used for the preparation of devices that do not require high precision, such as the preparation of discrete components of lenses or the preparation of medium and small scale integrated circuits.

The mask plate for proximity exposure and contact exposure can be used in general. The mask plate includes a light-transmitting substrate and an opaque layer formed on the light-transmitting substrate. At present, the mask plate for proximity exposure and contact exposure is both In order to flatten the mask plate, that is, the heights of the top surface of the light-transmitting substrate and the top surface of the opaque layer are approximately equal, so that the top surface of the entire mask plate is approximately flat. When using this flat mask plate for contact exposure of a substrate with pits, due to the long distance between the opaque layer and the bottom of the pits, the edge of the pattern formed after exposure is relatively blurred, and the resolution and accuracy of the pattern are reduced. , the accuracy and stability of the device are also reduced.

The purpose of the present invention is to provide a mask plate and a preparation method thereof, which can improve the resolution and precision of a pattern formed after proximity exposure of a substrate with pits.

In order to achieve the above object, the present invention provides a method for preparing a mask plate, comprising:

providing a bottom mold having a plurality of grooves therein, the grooves extending from a top surface of the bottom mold into the bottom mold;

forming an opaque layer in the groove, the opaque layer covering at least the bottom of the groove;

forming a light-transmitting transition layer on the bottom mold, and covering the light-transmitting transition layer with a light-transmitting substrate; and,

The bottom mold is released from the mold to form the mask plate.

Optionally, the opaque layer completely fills the groove; or, the opaque layer fills a part of the depth of the groove, and the light-transmitting transition layer fills the remaining depth of the groove.

The first glue material is coated on the bottom mold and cured to form the light-transmitting transition layer; or, the first glue material is dropped onto the bottom mold and pressed and cured to form the light-transmitting transition layer.

Optionally, when the first glue material is a thermosetting glue, the first glue material is heated for curing; when the first glue material is a photosensitive glue, light of a predetermined wavelength is used to irradiate the first glue material. glue for curing.

Optionally, coating a first adhesive material on the bottom mold and standing to solidify to form the light-transmitting transition layer, wherein the first adhesive material is a hardened adhesive, and the edge of the bottom mold has a blocking ring .

Optionally, after coating the first adhesive material on the bottom mold and before curing the first adhesive material, the light-transmitting substrate is covered.

Optionally, the step of forming the opaque layer in the groove includes:

A second glue material is dropped into the groove and cured to form the opaque layer, and the second glue material is opaque to light.

Optionally, when the second glue material is a thermosetting glue, the second glue material is heated for curing; when the second glue material is a photosensitive glue, light of a predetermined wavelength is used to irradiate the second glue material. The glue material is cured; when the second glue material is a hardened glue, the second glue material is allowed to stand for curing.

The present invention also provides a mask plate, comprising:

light-transmitting substrate;

a light-transmitting transition layer on the light-transmitting substrate; and,

A plurality of opaque layers are distributed on the light-transmitting transition layer and protrude from the light-transmitting transition layer.

Optionally, the distance between the top surface of the opaque layer and the top surface of the light-transmitting substrate is greater than or equal to 100 microns.

In the mask plate and its preparation method provided by the present invention, a bottom mold with grooves is provided first, then a light-tight layer is formed in the grooves, and then a light-transmitting transition layer is formed on the bottom mold and covered with a light-transmitting substrate , the light-transmitting transition layer can be used as an adhesive layer between the light-transmitting substrate and the opaque layer, so as to facilitate the release of the bottom mold, and after the mold is released, the mask plate is formed. In the present invention, the opaque layer protrudes from the light-transmitting substrate, and when the mask plate is used to expose the substrate with pits, the opaque layer can extend into the pits of the substrate, thereby reducing the distance between the bottom of the pit and the bottom of the pit. The distance between them increases the sharpness and definition of the edge of the pattern formed after exposure, thereby improving the precision and reliability of the device.

Further, by controlling the depth of the groove, the outwardly protruding distance of the opaque layer relative to the light-transmitting substrate can be controlled, thereby being able to accommodate the preparation of more devices.

Further, the first glue material and the second glue material are cured by heating or exposure, which can reduce the curing time and improve the preparation efficiency.

Further, the first adhesive material can also be subjected to a lamination treatment during curing, which further reduces the curing time, and can reduce the thickness of the light-transmitting transition layer, thereby increasing the process window during the preparation of the mask plate.

The specific embodiments of the present invention will be described in more detail below with reference to the schematic diagrams. The advantages and features of the present invention will become more apparent from the following description. It should be noted that, the accompanying drawings are all in a very simplified form and in inaccurate scales, and are only used to facilitate and clearly assist the purpose of explaining the embodiments of the present invention.

Example 1

FIG. 1 is a flowchart of a method for preparing a mask plate provided in this embodiment. As shown in Figure 1, the mask plate includes:

Step S1: providing a bottom mold with a plurality of grooves in the bottom mold, and the grooves extend from the surface of the bottom mold into the bottom mold;

Step S2: forming an opaque layer in the groove, the opaque layer covering at least the bottom of the groove;

Step S3: forming a light-transmitting transition layer on the bottom mold, and covering the light-transmitting transition layer with a light-transmitting substrate; and,

Step S4: releasing the bottom mold from the mold to form the mask plate.

Specifically, please refer to FIGS. 2 to 6 , which are schematic structural diagrams corresponding to the corresponding steps of the method for preparing the mask plate. Next, the method for preparing the mask plate provided by the present embodiment will be described with reference to FIGS. 2 to 6 . For further description, and for the convenience of description, this embodiment will be described by taking the preparation of a mask plate for an aperture of a camera as an example. It should be understood that the method for preparing a mask plate provided by the present invention can also be used to prepare other mask plates. It can be understood that the mask plate in this embodiment can be used for contact exposure or proximity exposure, and this embodiment will be described by taking the mask plate used for proximity exposure as an example.

Referring to FIG. 2 , step S1 is first performed to provide a bottom mold 100 , the bottom mold 100 has a plurality of grooves 101 , and the grooves 101 extend from the top surface of the bottom mold 100 to the bottom mold 100 inside the bottom mold 100 . a certain depth. The grooves 101 will correspond to the opaque patterns on the mask plate, and different opaque patterns can be prepared by designing the shape and distribution of the grooves 101 . In this embodiment, since the mask plate is used to prepare the aperture of the camera, the shape of the grooves 101 is circular and distributed in an array on the bottom mold 100 .

Please continue to refer to FIG. 2 , the edge of the bottom mold 100 has a blocking ring 102 , and the blocking ring 102 is a baffle that surrounds the bottom mold 100 in a circle. The shielding ring 102 has a certain height, so as to prevent the problem of glue overflowing in the subsequent process, and can better control the thickness uniformity of the glue material coated in the subsequent process.

In this embodiment, the bottom mold 100 is a metal mold, and the groove 101 is machined on the metal mold by a numerical control machine tool. As an optional embodiment, the bottom mold 100 may also be a plastic mold, which is not limited in the present invention. Further, the shielding ring 102 and the bottom mold 100 are integrally formed to simplify the manufacturing process of the bottom mold 100, but not limited thereto.

Please refer to FIG. 3 , step S2 is performed, and a second glue material is dropped into the groove 101 until the second glue material completely fills the groove 101 , and then the second glue material is cured to form the groove 101 . The opaque layer 201 is described. Optionally, the second glue material may be thermosetting glue, photosensitive glue or hardened glue. When the second glue material is a thermosetting glue, the second glue material is heated to be cured; When the second glue material is a photosensitive glue, the second glue material is irradiated with light of a predetermined wavelength for curing; when the second glue material is a hardened glue, the second glue material is left to stand for curing. Further, the photosensitive glue is, for example, UV glue, which is cured by irradiation with UV light; the hardening glue is, for example, AB glue or silicone glue, which can be cured after standing.

It should be understood that since the glue material is usually light-transmitting, before the second glue material is dropped into the groove 101 , black dye needs to be dropped into the second glue material, so that the second glue material needs to be dropped into the second glue material. The glue material is black (as required, other color dyes can also be used, as long as the light can be blocked during the exposure process), and the opaque layer 201 formed after curing can be opaque to light. Of course, the second glue material can also be directly selected from the black glue material, omitting the step of dripping the black dye.

Since the second adhesive material completely fills the groove 101 , the opaque layer 201 also completely fills the groove 101 . As can be seen from FIG. 3 , each of the grooves 101 has an opaque layer 201 , and the thickness of the opaque layer 201 is equal to the depth of the groove 101 . In this way, by controlling The depth of the groove 101 can control the thickness of the opaque layer 201 .

Referring to FIG. 4 , step S3 is executed, coating a first adhesive material on the top surface of the bottom mold 100 and immediately covering the light-transmitting substrate 203 , so that the first adhesive material adheres to the light-transmitting substrate 203 at the same time and on the opaque layer 201 . In this embodiment, the first adhesive material is a hardened adhesive, which can be cured by standing, and the cured first adhesive material forms the light-transmitting transition layer 202 . Since the edge of the bottom mold 100 is shielded by the shielding ring 102 , the first adhesive material will not overflow the bottom mold 100 when standing still.

It should be understood that the light-transmitting transition layer 202 can be used as an adhesive layer to bond the light-transmitting substrate 203 and the opaque layer 201 together, even if the volume shrinkage of the second adhesive material after curing causes the The top surface of the opaque layer 201 is slightly lower than the notch of the groove 101, and the first adhesive material can also flow into the groove 101 to form a good contact with the opaque layer 201, which is convenient for demolding . Moreover, since the light-transmitting transition layer 202 can transmit light, the opaque pattern of the mask plate will not be changed.

Referring to FIG. 5 , step S4 is performed, and the bottom mold 100 is released from the mold to form the mask plate as shown in FIG. 6 . Since the light-transmitting transition layer 202 adheres the opaque layer 201 , the bottom mold 100 can be easily demolded without damaging the opaque layer 201 .

Please continue to refer to FIG. 6, this embodiment also provides a mask version, including:

The light-transmitting substrate 203, the light-transmitting substrate 203 is a glass or quartz glass (quartz) substrate, but not limited to this;

The light-transmitting transition layer 202 is located on the light-transmitting substrate 203;

A plurality of opaque layers 201 are distributed on the translucent transition layer 202 and protrude from the translucent transition layer 202. The translucent transition layer 202 connects the translucent substrate 203 with the opaque transition layer 202. Layers 201 are bonded together.

In this embodiment, the distance between the top surface of the opaque layer 201 and the top surface of the transparent substrate 203 is greater than or equal to 100 μm, so that the opaque layer 201 protrudes outwards, the The mask version is no longer a flat structure, but a three-dimensional structure.

7a and 7b are schematic diagrams of exposing a substrate 300 by using the mask plate. As shown in FIG. 7a and FIG. 7b, the substrate 300 is a substrate 300 for forming a camera (specifically, the lens of the camera), and the substrate 300 has a number of cavities 301 (only schematic in FIG. 7a and FIG. 7b). A pocket 301 is shown) extending from the top surface of the substrate 300 to a depth within the substrate 300 . The top surface of the substrate 300 is covered with a layer to be exposed 302, and at least part of the bottom of the cavity 301 is raised upward to form a protrusion 303. The layer to be exposed 302 on the protrusion 303 needs to be removed by exposure, thereby Forms the aperture of the camera.

When the substrate 300 is exposed by the mask plate, the opaque layer 201 can protrude into the cavity 301 so that the top surfaces of the opaque layer 201 and the protruding portion 303 The exposure distance d between them is reduced, so that the sharpness and definition of the edge of the exposed pattern are improved, and the imaging definition of the formed camera is further improved.

8a and 8b are partial schematic diagrams of apertures formed under two different exposure distances d provided in this embodiment. Among them, the exposure distance d=500 microns in FIG. 8a, and the exposure distance d=100 microns in FIG. 8b, that is to say, the pattern of the opaque layer 201 of the mask plate used in FIGS. 8a and 8b is the same, and the area is , the thickness of the opaque layer 201 of the mask plate used in FIG. It can be seen from Fig. 8a and Fig. 8b that the smaller the exposure distance d, the better the sharpness and definition of the edge of the pattern formed after exposure. Therefore, the mask plate provided in this embodiment is relatively flat compared to the prior art. For the mask version, it can improve the sharpness and definition of the edge of the pattern formed after exposure.

Embodiment 2

9 to 12 are schematic structural diagrams corresponding to corresponding steps of the method for preparing a mask plate provided in this embodiment. Referring to FIG. 9 , the difference from the first embodiment is that in this embodiment, when step S2 is performed, only a relatively small amount of the second glue material is dropped into the groove 101 , so that the second glue material is filled with Part of the groove 101 is formed, and then the second glue material is cured to form the opaque layer 201 .

Since the second adhesive material only fills part of the groove 101 , the opaque layer 201 also fills part of the depth of the groove 101 . As can be seen from FIG. 9 , each of the grooves 101 has an opaque layer 201 , and the top surface of the opaque layer 201 is lower than the notch of the groove 101 .

Please refer to FIG. 10 , step S3 is executed, and a first adhesive material is coated on the top surface of the bottom mold 100 and immediately covers the light-transmitting substrate 203 , the first adhesive material will flow into the groove 101 to fill up For the remaining depth of the groove 101 , the first adhesive material is allowed to stand and solidify to form the light-transmitting transition layer 202 , and the light-transmitting transition layer 202 fills the non-transmitting part of the groove 101 . The filled portion of layer 201.

In this embodiment, since the opaque layer 201 only fills a part of the depth of the groove 101 , the contact surface with the bottom mold 100 is less, which is more favorable for demolding.

Please refer to FIG. 11 and FIG. 12 , step S4 is executed, and the mask plate is formed after the bottom mold 100 is released from the mold. The difference from the first embodiment is that the light-transmitting transition layer in the mask plate in this embodiment is The top surface of 202 is not a flat surface, but has several protrusions, and the opaque layer 201 is located on the protrusions of the light-transmitting transition layer 202 . When the mask plate is used for exposure, the protrusions of the light-transmitting transition layer 202 and the opaque layer 201 can protrude into the cavities of the substrate together.

Embodiment 3

13 to 14 are schematic structural diagrams corresponding to corresponding steps of the method for preparing a mask plate provided in this embodiment. Please refer to FIG. 13 and FIG. 14 . The difference from the second embodiment is that in this embodiment, the edge of the bottom mold 100 does not have a blocking ring. When step S3 is performed, a first adhesive material is coated on the bottom mold 100 and curing to form the light-transmitting transition layer 202, the first adhesive material is a thermosetting adhesive and photosensitive adhesive, and the first adhesive material is heated to cure or irradiate the first adhesive material with light of a predetermined wavelength to to cure. Compared with static curing, the curing speed of heat curing or light irradiation curing is faster, and the first adhesive material is usually cured quickly without overflowing the bottom mold 100 , so there is no need to fix the bottom mold 100 . Set occlusion rings around the edges. Also, increasing the curing speed can also improve the efficiency of the preparation.

Embodiment 4

15 to 17 are schematic structural diagrams corresponding to corresponding steps of the method for preparing a mask plate provided in this embodiment. Referring to FIG. 15 , the difference from the third embodiment is that in this embodiment, when step S3 is performed, the first adhesive material is dropped on the bottom mold 100 , and the first adhesive is heated and cured or cured. curing by light, and pressing the first glue material at the same time. For example, when the first glue material is a thermosetting glue, after the first glue material is dropped on the bottom mold 100, a high temperature pressing head is used to press the first glue material, The first adhesive material is extended to the entire top surface of the bottom mold 100, and the first adhesive material is also cured at the same time; when the first adhesive material is photosensitive adhesive, on the bottom mold 100 After the first glue material is dropped, while the first glue material is irradiated with light of a predetermined wavelength, a light-transmitting pressing head is used to press the first glue material, so that the first glue material is It is extended to the entire top surface of the bottom mold 100, and at the same time, the first glue material is also cured.

The first glue material is preferably dropped in the center of the bottom mold 100, and the amount of drop is small to prevent glue overflow, and the rate of forming the light-transmitting transition layer 202 by one-time pressing and curing is faster. , further improving the preparation efficiency.

Please refer to FIG. 16 and FIG. 17 , step S4 is executed, and the mask plate is formed after the bottom mold 100 is released from the mold. The difference from the third embodiment is that the light-transmitting transition layer 202 is formed by pressing. The thickness is thinner, and the distribution on the light-transmitting substrate 203 is relatively uniform.

Embodiment 5

18 to 20 are schematic structural diagrams of the bottom mold of the mask plate provided in this embodiment. Please refer to FIGS. 18 to 20 . The difference from the first embodiment is that in this embodiment, the shielding ring 102 of the bottom mold 100 has a plurality of glue overflow openings 102 a , and the glue overflowing openings 102 a extend from the shielding ring 102 The top surface of the bottom mold 100 extends to a certain depth in the shielding ring 102. When step S3 is performed, the first glue material is coated on the bottom mold 100. When the first glue material is excessive, it can pass through the The glue overflow port 102a discharges the excess first glue material.

In this embodiment, the number of the glue overflow openings 102a is 4, and the four glue overflow openings 102a are symmetrically distributed, but not limited to this; further, the shape of the glue overflow openings 102a may be a semicircle shape, square or trapezoid, etc., and will not be illustrated one by one here.

It should be understood that the "light transmission" referred to herein can also be referred to as "completely light transmission", and its light transmittance is, for example, greater than or equal to 98%, which can be approximately regarded as being able to transmit all light; It can be called "completely opaque", and its light transmittance is, for example, less than or equal to 2%, which can be approximately regarded as being able to block all light. It should be understood that the light transmittances of "transmitting" and "opaque" are not limited to the ranges described above, and the so-called "transmitting" is only a higher transmittance relative to "opaque", and does not mean complete transmittance , the so-called "opaque" only has a lower light transmittance relative to "transparent", it does not mean that it is completely opaque, and the corresponding "transparent" and "opaque" can be based on the actual process needs. Light rate range.

To sum up, in the mask plate and its preparation method provided by the present invention, a bottom mold with grooves is first provided, then a light-tight layer is formed in the grooves, and then a light-transmitting transition layer is formed on the bottom mold and covered The light-transmitting substrate and the light-transmitting transition layer can be used as an adhesive layer between the light-transmitting substrate and the opaque layer, so as to facilitate the release of the bottom mold, and after the mold is released, the mask plate is formed. In the present invention, the opaque layer protrudes from the light-transmitting substrate, and when the mask plate is used to expose the substrate with pits, the opaque layer can extend into the pits of the substrate, thereby reducing the distance between the bottom of the pit and the bottom of the pit. The distance between them increases the sharpness and definition of the edge of the pattern formed after exposure, thereby improving the precision and reliability of the device. Further, by controlling the depth of the groove, the outwardly protruding distance of the opaque layer relative to the light-transmitting substrate can be controlled, thereby being able to accommodate the preparation of more devices. Further, the first glue material and the second glue material are cured by heating or exposure, which can reduce the curing time and improve the preparation efficiency. Further, the first adhesive material can also be subjected to a lamination treatment during curing, which further reduces the curing time, and can reduce the thickness of the light-transmitting transition layer, thereby increasing the process window during the preparation of the mask plate.

The above are only preferred embodiments of the present invention, and do not have any limiting effect on the present invention. Any person skilled in the art, within the scope of not departing from the technical solution of the present invention, makes any form of equivalent replacement or modification to the technical solution and technical content disclosed in the present invention, all belong to the technical solution of the present invention. content still falls within the protection scope of the present invention.

100: Bottom mold 101: Grooves 102: Occlusion Ring 102a: Glue overflow 201: Opaque layer 202: Translucent transition layer 203: Light-transmitting substrate 300: base 301: Pit 302: layer to be exposed 303: Projection d: exposure distance S1~S4: Steps

Fig. 1 is the flow chart of the preparation method of the mask plate provided by Embodiment 1 of the present invention; 2 to 6 are schematic structural diagrams corresponding to the corresponding steps of the method for preparing a mask plate according to Embodiment 1 of the present invention, wherein, FIG. 6 is a schematic structural diagram of the mask plate; 7a-7b are schematic diagrams of exposing a substrate by using a mask plate according to Embodiment 1 of the present invention; 8a-8b are partial schematic diagrams of apertures formed under two different exposure distances provided by Embodiment 1 of the present invention; 9 to 12 are schematic structural diagrams corresponding to corresponding steps of the method for preparing a mask plate according to Embodiment 2 of the present invention, wherein FIG. 12 is a schematic structural diagram of the mask plate; 13 to 14 are schematic structural diagrams corresponding to corresponding steps of the method for preparing a mask plate according to Embodiment 3 of the present invention; 15 to 17 are schematic structural diagrams corresponding to corresponding steps of the method for preparing a mask plate provided in Embodiment 4 of the present invention, wherein FIG. 17 is a schematic structural diagram of the mask plate; 18 to 20 are schematic structural diagrams of the bottom mold of the mask plate according to the fifth embodiment of the present invention.

S1~S4: Steps

Claims (10)

A method for preparing a mask plate, comprising: providing a bottom mold having a plurality of grooves therein, the grooves extending from a top surface of the bottom mold into the bottom mold; forming an opaque layer in the groove, the opaque layer covering at least the bottom of the groove; forming a light-transmitting transition layer on the bottom mold, and covering the light-transmitting transition layer with a light-transmitting substrate; and, The bottom mold is released from the mold to form the mask plate. The method for preparing a mask plate according to claim 1, wherein the opaque layer completely fills the groove; or, the opaque layer fills a part of the depth of the groove, and the light transmission transitions layer fills the remaining depth of the groove. The method for preparing a mask plate according to claim 1, wherein a first adhesive material is coated on the bottom mold and cured to form the light-transmitting transition layer; or, the first adhesive material is dropped onto the bottom mold is laminated and cured to form the light-transmitting transition layer. The method for preparing a mask plate according to claim 3, wherein when the first glue material is a thermosetting glue, the first glue material is heated for curing; when the first glue material is a photosensitive glue , using light of a predetermined wavelength to irradiate the first glue material for curing. The method for preparing a mask plate according to claim 1, wherein a first glue material is coated on the bottom mold and left to solidify to form the light-transmitting transition layer, wherein the first glue material is a hardening glue , and the edge of the bottom mold has a blocking ring. The method for preparing a mask plate according to claim 3 or 5, wherein the light-transmitting substrate is covered after coating the first glue material on the bottom mold and before curing the first glue material. The method for preparing a mask plate according to claim 1, wherein the step of forming an opaque layer in the groove comprises: A second glue material is dropped into the groove and cured to form the opaque layer, and the second glue material is opaque to light. The method for preparing a mask plate according to claim 7, wherein when the second glue material is a thermosetting glue, the second glue material is heated for curing; when the second glue material is a photosensitive glue , using light with a predetermined wavelength to irradiate the second glue material to cure; when the second glue material is a hardened glue, let the second glue material stand for curing. A mask version, characterized in that it includes: light-transmitting substrate; a light-transmitting transition layer on the light-transmitting substrate; and A plurality of opaque layers are distributed on part of the light-transmitting transition layer and protrude from the light-transmitting transition layer. The mask plate of claim 9, wherein the distance between the top surface of the opaque layer and the top surface of the light-transmitting substrate is greater than or equal to 100 microns.

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