Method for manufacturing photosensitive polymer dielectric layer on patterned substrate

Abstract

The invention discloses a method for manufacturing a photosensitive polymer dielectric layer on a patterned substrate, which comprises the following steps of: cleaning the surface of the substrate by using plasma, and baking the cleaned substrate; coating a photosensitive polymer medium adhesive by adopting a dynamic adhesive dripping method, starting to drip the photosensitive polymer medium adhesive at a constant speed at a high rotating speed of the substrate, continuously dripping the adhesive until the substrate rotates at a low rotating speed, keeping adhesive uniformizing at a low rotating speed until the adhesive uniformizing is finished after the adhesive dripping is stopped, and performing soft baking on the coated substrate; performing alignment exposure on the substrate by using ultraviolet light matched with a patterned mask; developing the substrate by using a developing solution to obtain a graphical medium glue layer; and curing the graphical dielectric glue layer in an anaerobic high-temperature environment to obtain the graphical dielectric layer. According to the invention, the coverage problem of traditional static coating can be solved, and the manufacturing of a bubble-free, high-uniformity and high-adhesion polymer dielectric layer is realized.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of semiconductor manufacturing and microelectronic processing, and particularly relates to a method for manufacturing a photosensitive polymer dielectric layer on a patterned substrate. BACKGROUND

[0002] Photosensitive polymer dielectric material is a kind of polymer material with electrical insulation performance (dielectric property) and photosensitive patterning capability. It is widely used in advanced packaging, MEMS (micro-electro-mechanical system) and three-dimensional integration fields due to its excellent dielectric properties, mechanical strength, thermal stability and photosensitive characteristics. The main system at present is PSPI (photosensitive polyimide), photosensitive polybenzoxazole (photosensitive PBO), and photosensitive benzocyclobutene (photosensitive BCB). Compared with traditional non-photosensitive PI, PBO and BCB, photosensitive polymer dielectric material eliminates the complex steps of additional coating of photoresist on the dielectric layer and etching, simplifies the process flow, reduces the cost and avoids the damage to the dielectric material itself in the etching process.

[0003] In the fields of advanced packaging, MEMS (micro-electro-mechanical system) and three-dimensional integration, the dielectric layer is a core step in the rerouting process, and plays an important role in electrical insulation, mechanical support, physical protection, stress buffering and surface planarization. The dielectric layer often needs to be prepared on a patterned substrate which has already has topological structures such as circuits, bumps or grooves. However, when coating photosensitive polymer glue on the patterned substrate, there are serious challenges. The traditional static glue dropping method is prone to problems such as poor coverage of photosensitive polymer dielectric, such as air bubbles, uneven coating, incomplete filling of glue, etc., because of the large difference in surface energy of different materials or the large ups and downs of the surface. This will lead to defects in the pattern after exposure and development, such as line breakage, bridging or size distortion, and greatly increase the risk of sticking in the subsequent contact exposure, seriously affecting the yield, performance and reliability of the product.

[0004] Therefore, there is an urgent need for a photolithography process for photosensitive polymer dielectric layer on a patterned substrate to solve the problems of uniformity of coating, defect-free filling and pattern fidelity. SUMMARY

[0005] The purpose of the present application is to provide a method for manufacturing a photosensitive polymer dielectric layer on a patterned substrate, which can solve the coverage problem of traditional static coating and realize the manufacture of polymer dielectric layer with no air bubbles, high uniformity and high adhesion.

[0006] In order to achieve the above purpose, one aspect of the present application provides a method for manufacturing a photosensitive polymer dielectric layer on a patterned substrate, comprising: Step S1, cleaning the surface of the substrate using plasma, and baking the cleaned substrate; Step S2, a dynamic drop glue method is used to coat the photosensitive polymer medium glue, the photosensitive polymer medium glue is started to be added at a high rotation speed of the substrate, the glue adding is continuously performed until the substrate rotates at a low rotation speed, the glue adding is stopped, and the glue is maintained at the low rotation speed until the glue adding is finished, and the coated substrate is subjected to soft baking; Step S3, the substrate is subjected to alignment exposure by using ultraviolet light and a patterned mask plate; Step S4, the substrate is developed by using a developing solution, and a patterned medium glue layer is obtained. Step S5, the patterned medium glue layer is cured in an anaerobic high-temperature environment, and a patterned medium layer is obtained.

[0007] According to the method for manufacturing the photosensitive polymer medium layer on the patterned substrate provided by the application, the process operation is simple, the process compatibility is high, the covering problem of the traditional static coating can be solved, and the polymer medium layer with no bubble, high uniformity and high adhesion can be manufactured. BRIEF DESCRIPTION OF DRAWINGS

[0008] In order to more clearly illustrate the technical solutions of the present application, the following will briefly introduce the drawings used in the description of the embodiments of the present application. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings: Figure 1 is the overall flowchart of the method for manufacturing the photosensitive polymer medium layer on the patterned substrate according to an embodiment of the present application. DETAILED DESCRIPTION

[0009] In order to make the purpose, technical solutions and advantages of the present application more clear, the technical solutions of the present application will be described clearly and completely in the following with reference to the drawings. Obviously, the described embodiments are only some embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the present application.

[0010] An embodiment of the present application provides a method for manufacturing a photosensitive polymer medium layer on a patterned substrate, as shown in Figure 1 The method of the embodiment of the present application includes the following steps S1-S5.

[0011] Step S1, substrate pretreatment: the surface of the patterned substrate 2 is cleaned by using plasma 1 to remove organic contaminants and activate the surface. Subsequently, the substrate 2 is placed on a hot plate to bake to remove the adsorbed water on the surface. The gas used for plasma cleaning is argon or oxygen, the power is 100-500W, and the time is 1-10min.

[0012] In one embodiment, a plasma cleaning apparatus is used to clean the patterned substrate surface with Ar gas as the process gas, at a cleaning power of 200 W and a cleaning time of 2 min, to remove organic contaminants and activate the surface. Subsequently, the substrate is baked on a hot plate at a temperature of 150 °C for 5 min to remove the water adsorbed on the surface.

[0013] Step S2, dynamic drop coating: the photosensitive polymer medium glue 3 is coated using a dynamic drop coating method. When the substrate 2 is rotating at a high speed, the photosensitive polymer medium glue 3 is started to be added at a constant speed; the drop coating is continued until the substrate 2 is rotating at a low speed and maintained for a period of time; after the drop coating is stopped, the glue is maintained at a low speed until the end of the glue coating. Finally, the coated substrate 2 is soft-baked to volatilize part of the solvent.

[0014] In one embodiment, the photosensitive polymer medium glue has a viscosity of 200-1500 cp, the high-speed dynamic drop coating time is 3-15 sec, and the rotation speed is 1500-4500 rpm; the low-speed dynamic drop coating time is 3-15 sec, and the rotation speed is 500-2000 rpm; the low-speed glue coating time is 30-120 sec, and the rotation speed is 500-2000 rpm; and the total drop coating amount is 1-15 ml.

[0015] In one embodiment, the WPR5100 glue is coated using a dynamic drop coating method. Using a pipette, when the substrate is rotating at a high speed of 3000 rpm, the WPR5100 glue is started to be added at a constant speed, and this high-speed dynamic drop coating process lasts for 8 sec; the drop coating is continued until the substrate is rotating at a low speed of 1000 rpm and maintained for 7 sec, and the total drop coating amount is 10 ml; after the drop coating is stopped, the glue is maintained at a rotation speed of 1000 rpm for 60 sec, so that the glue fills the concave-convex structure of the patterned substrate under the joint action of the centrifugal force and the surface tension. Finally, the coated substrate is soft-baked at 100 °C for 5 min to volatilize part of the solvent.

[0016] Step S3, patterned exposure: using ultraviolet light 4, a pre-designed pattern mask 5 is used for overlay exposure.

[0017] In one embodiment, an SUSS MA8 ultraviolet exposure machine is used, and a pre-designed pattern mask is used for exposure, with an exposure dose of 650 mJ / cm 2 , and the WPR5100 in the exposed area undergoes a chemical reaction.

[0018] Step S4, patterned development: the exposed substrate 2 is developed using a suitable developing solution to dissolve the unexposed (or exposed, depending on whether the photosensitive polymer medium glue is positive or negative glue) area, to obtain a patterned medium glue layer 6.

[0019] In one embodiment, the exposed substrate is developed using a TMAH 2.38% developing solution, with a developing time of 200 seconds, to dissolve the WPR5100 in the exposed areas in step S3, to obtain a patterned photosensitive polymer medium material.

[0020] In step S5, the developed substrate is placed in an anaerobic environment for high-temperature curing. A final stable patterned polymer medium 7 is formed.

[0021] In one embodiment, the curing is performed using an anaerobic oven, with a curing temperature of 200°C and a curing time of 1 hour.

[0022] In summary, the method for manufacturing a photosensitive polymer medium layer on a patterned substrate according to the embodiments of the present application solves the problem of coverage when a photosensitive polymer medium glue is statically coated on a complex patterned medium surface, without affecting the final lithography pattern, by designing the pre-treatment and dynamic glue dropping steps, to achieve a bubble-free, high-uniformity, high-adhesion polymer medium layer manufacturing.

[0023] Furthermore, the method for manufacturing a photosensitive polymer medium layer on a patterned substrate according to the embodiments of the present application can significantly improve the coverage of the photosensitive polymer on the complex surface of the patterned substrate by using the secondary dynamic glue dropping method in the manufacturing process of the photosensitive polymer medium layer, which is conducive to reducing the glue dropping cost and improving the single-step process yield of the medium layer manufacturing.

[0024] The above only describes certain exemplary embodiments of the present application by way of illustration, and it is needless to say that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present application. Therefore, the above figures and descriptions are illustrative in nature and should not be construed as limiting the scope of the claims of the present application.

Claims

1. A method of fabricating a photosensitive polymer dielectric layer on a patterned substrate, characterized by, The method comprises the following steps: S1, cleaning the surface of the substrate by using plasma, and baking the cleaned substrate; S2, coating a photosensitive polymer medium glue by using a dynamic glue dropping method, starting to drop the photosensitive polymer medium glue at a high rotation speed of the substrate, continuously dropping the glue until the substrate rotates at a low rotation speed, stopping the glue dropping, maintaining the glue dropping at the low rotation speed until the glue dropping is finished, and soft-baking the coated substrate; S3, performing alignment exposure on the substrate by using ultraviolet light and a patterned mask plate; S4, developing the substrate by using a developing solution to obtain a patterned medium glue layer; S5, curing the patterned medium glue layer in an anaerobic high-temperature environment to obtain a patterned medium layer.

2. The method of claim 1, wherein, In step S2, the dynamic glue dropping time at the high rotation speed is 3-15 seconds, the rotation speed is 1500-4500 rpm, the dynamic glue dropping time at the low rotation speed is 3-15 seconds, the rotation speed is 500-2000 rpm, and the low-speed glue spreading time is 30-120 seconds, the rotation speed is 500-2000 rpm.

3. The method according to claim 1 or 2, characterized in that, In step S2, the total glue dropping amount is 1-15 ml.

4. The method according to claim 1 or 2, characterized in that, In step S1, the substrate is cleaned by using a plasma cleaning device, argon or oxygen is used as the cleaning gas, the cleaning power is 100-500 W, and the cleaning time is 1-10 min.

5. The method according to claim 1 or 2, characterized in that, In step S1, the substrate is baked on a hot plate, the baking temperature is 100-180°C, and the baking time is 1-10 min.

6. The method of claim 1 or 2, wherein, In step S2, the viscosity of the photosensitive polymer medium glue is 200-1500 cp.

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