Application of a flat carrier in wafer loading

Abstract

The present invention discloses an application of a planar carrier in wafer carrying, and the application method specifically includes the following steps: S1, bonding a glass carrier after completing the front-end process, then thinning the back of the wafer and completing the back-end process of the wafer; S2, spraying a water film on the back of the wafer, attaching a silicon carrier, then flipping the glass carrier, wafer and silicon carrier as a whole, and finally debonding and removing the glass carrier; S3, baking to volatilize the water film, coating SOG on the edge of the wafer for blocking, removing the adhesive, and completing the front-end process of the wafer; S4, attaching a planar carrier on the front, flipping the silicon carrier, wafer and planar carrier as a whole, disconnecting SOG through a laser ring, and removing the silicon carrier; S5, carrying the wafer through the planar carrier to complete the subsequent wafer process. The present invention carries the wafer through the silicon carrier and the planar carrier, and does not need to use an adhesive for bonding, which overcomes the temperature limit of the high-temperature process. At the same time, the carrier is simple to make and the material cost is also lower.

Description

Technical Field

[0001] The present invention relates to the technical field of wafer processing, and in particular to an application of a planar carrier in wafer carrying. Background Art

[0002] In integrated circuit device manufacturing equipment, the wafer carrier plays a very important role. It is usually used to hold the wafer so that the wafer can be processed or just temporarily placed. If the wafer carried by the wafer carrier is offset relative to the wafer carrier, it will cause process deviation in the subsequent process and cause yield loss; or in the process of transferring the wafer by a robotic arm, the wafer will be offset relative to the target position, which may cause the wafer to be hit and broken.

[0003] In order to facilitate the loading and transfer of wafers during processing, the currently widely used method is to use a glass carrier as a medium to carry the wafers. However, the use of glass carriers to carry wafers requires the use of adhesives for bonding, and adhesives have poor high temperature resistance and cannot meet the needs of high temperature wafer processes. Therefore, a new wafer carrying method is urgently needed to overcome the problem that high temperature process wafers cannot be stably limited. Summary of the invention

[0004] In order to solve the deficiencies mentioned in the above background technology, the purpose of the present invention is to provide an application of a planar carrier in wafer carrying. The present invention carries the wafer through a silicon carrier and a planar carrier, and does not need to use an adhesive for bonding, thereby overcoming the temperature limitation of the high-temperature process. At the same time, the carrier is simple to manufacture and the material cost is lower.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] An application of a planar carrier in wafer loading, wherein a plurality of air extraction holes for adsorbing wafers are provided on the surface of the planar carrier, and the application method specifically comprises the following steps:

[0007] S1, bonding a glass carrier to the front side of the wafer after the front side front-end process is completed by adhesive, and then thinning the back side of the wafer by grinding / etching, and completing the back side front-end process of the wafer;

[0008] S2, spray deionized water on the back of the wafer to form a water film of uniform thickness, then attach a silicon carrier to the back of the wafer, and use the attraction between water molecules and the external atmospheric pressure to make the silicon carrier and the wafer adsorb, then flip the glass carrier, wafer and silicon carrier as a whole, apply SOG at at least two points on the edge of the wafer for positioning, and finally debond and remove the glass carrier;

[0009] S3, sending the silicon carrier and the wafer to a constant temperature drying device for baking, so that the water film between the silicon carrier and the wafer evaporates, and then using a spin coating medium SOG or polyimide to seal the edge of the wafer, and then using an organic solvent to dissolve and remove the adhesive, completing the wafer front end back-end process;

[0010] S4, coating polyimide on the front side of the wafer to flatten the front side, then attaching a flat carrier to the front side of the wafer, extracting air through the exhaust holes of the flat carrier to make the wafer and the flat carrier adsorbed, then turning over the silicon carrier, the wafer and the flat carrier as a whole, cutting the silicon carrier and the wafer edge by laser to disconnect the blocking layer, release the bond between the silicon carrier and the wafer, and then lift and remove the silicon carrier;

[0011] S5. Carrying the wafer on a flat carrier plate completes subsequent wafer processing.

[0012] Further preferably, the front-end process in step S1 is all processes before the metal process on the front side of the wafer, including the ILD process and contact hole opening.

[0013] Further preferably, the back side front-end process in step S1 includes all processes before the wafer back side process, including ion implantation.

[0014] Further preferably, the front back-end process in step S3 includes a front metal process.

[0015] Further preferably, step S4 can also be to coat polyimide on the front side of the wafer to flatten the front side, then firstly cut the silicon carrier and the edge of the wafer by laser to disconnect the sealing layer, then attach the front side of the wafer to the flat carrier, and evacuate the air through the exhaust holes of the flat carrier to make the wafer and the flat carrier adsorbed, then flip the silicon carrier, wafer and flat carrier as a whole, and finally lift up and remove the silicon carrier.

[0016] Further preferably, in step S5, the subsequent wafer processes include a wafer back side metal process, a yellow light process, and a wafer cutting process.

[0017] Beneficial effects of the present invention:

[0018] The present invention utilizes a water film to fill the space between the wafer and the silicon carrier, and uses the attraction between water molecules and the external atmospheric pressure to adsorb the silicon carrier and the wafer, and at the same time, a dot-shaped seal is applied on the edge of the wafer to limit the displacement of the wafer in the plane direction, thereby fixing the wafer when the glass carrier is debonded. The present invention first bakes to remove the water film between the silicon carrier and the wafer before performing the front metal process, and then forms a comprehensive seal through SOG ring coating to ensure that the wafer will not bulge and crack due to the evaporation of the water film in the subsequent metal process. After completing the front process of the wafer, the present invention transfers the wafer to a flat carrier, and uses laser ring cutting of the silicon carrier and the edge of the wafer to disconnect the SOG, thereby releasing the connection between the wafer and the silicon carrier. In the process of the present invention, the wafer is carried by a silicon carrier and a flat carrier, and there is no need to use an adhesive for bonding, which overcomes the temperature limit of the high-temperature process. At the same time, the carrier is simple to manufacture and the material cost is lower. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be further described below in conjunction with the accompanying drawings.

[0020] Figure 1 is a process flow chart of step S1 of embodiment 1 of the present invention;

[0021] Figure 2 is a process flow chart of step S2 of embodiment 1 of the present invention;

[0022] Figure 3 is a process flow chart of step S3 of embodiment 1 of the present invention;

[0023] Figure 4 is a process flow chart of step S4 of Example 1 of the present invention;

[0024] Figure 5 It is a process flow chart of step S4 of Example 2 of the present invention. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] In the description of the present invention, it needs to be understood that a "carrier" is a carrier for carrying wafers, and its material may be silicon, graphite, glass or sapphire, etc., and is divided into a groove-type carrier (see the patent previously applied for by the applicant, patent application number: 2021114160788) and a flat carrier. The flat carrier is used in the present invention. There is no groove on the surface of the flat carrier, but a ventilation hole is provided in the middle like the groove-type carrier.

[0027] Example 1

[0028] An application of a planar carrier in wafer loading, characterized in that a plurality of air extraction holes for adsorbing wafers are provided on the surface of the planar carrier, and the application method specifically comprises the following steps:

[0029] S1. Bonding a glass carrier to the front side of the wafer after the ILD process and contact hole opening is done by adhesive, then thinning the back side of the wafer by grinding / etching, and completing the ion implantation process on the back side of the wafer;

[0030] S2, spray deionized water on the back of the wafer to form a water film of uniform thickness, then attach a silicon carrier to the back of the wafer, and use the attraction between water molecules and the external atmospheric pressure to make the silicon carrier and the wafer adsorb, then flip the glass carrier, wafer and silicon carrier as a whole, apply SOG at at least two points on the edge of the wafer for positioning, and finally debond and remove the glass carrier;

[0031] S3, sending the silicon carrier and the wafer to a constant temperature drying device for baking, so that the water film between the silicon carrier and the wafer evaporates, and then using the spin coating medium SOG to seal the edge of the wafer, and then using an organic solvent to dissolve and remove the adhesive, completing the metal process on the front side of the wafer;

[0032] S4, coating polyimide on the front side of the wafer to flatten the front side, then attaching a flat carrier to the front side of the wafer, extracting air through the exhaust holes of the flat carrier to make the wafer and the flat carrier adsorbed, then turning over the silicon carrier, the wafer and the flat carrier as a whole, cutting the edges of the silicon carrier and the wafer by laser to disconnect the SOG, release the bond between the silicon carrier and the wafer, and then lift and remove the silicon carrier;

[0033] S5. Carrying the wafer on a flat carrier plate completes subsequent wafer processing.

[0034] Example 2

[0035] An application of a planar carrier in wafer loading, characterized in that a plurality of air extraction holes for adsorbing wafers are provided on the surface of the planar carrier, and the application method specifically comprises the following steps:

[0036] S1, bonding the glass carrier to the front side of the wafer after the ILD process and contact hole opening by adhesive, then thinning the back side of the wafer by grinding / etching, and completing the particle implantation process on the back side of the wafer;

[0037] S2, spray deionized water on the back of the wafer to form a water film of uniform thickness, then attach a silicon carrier to the back of the wafer, and use the attraction between water molecules and the external atmospheric pressure to make the silicon carrier and the wafer adsorb, then flip the glass carrier, wafer and silicon carrier as a whole, apply SOG at at least two points on the edge of the wafer for positioning, and finally debond and remove the glass carrier;

[0038] S3, sending the silicon carrier and the wafer to a constant temperature drying device for baking, so that the water film between the silicon carrier and the wafer evaporates, and then using polyimide to seal the edge of the wafer, and then using an organic solvent to dissolve and remove the adhesive, completing the metal process on the front side of the wafer;

[0039] S4, after coating polyimide on the front side of the wafer to flatten the front side, cut the polyimide by laser cutting the silicon carrier and the edge of the wafer, attach the front side of the wafer to the flat carrier, and draw air through the exhaust holes of the flat carrier to make the wafer and the flat carrier adsorbed, then flip the silicon carrier, the wafer and the flat carrier as a whole, and finally lift and remove the silicon carrier;

[0040] S5. Carrying the wafer on a flat carrier plate completes subsequent wafer processing.

[0041] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. An application of a planar carrier in wafer loading, characterized in that: The surface of the planar carrier is provided with a plurality of exhaust holes for adsorbing wafers, and the application method specifically comprises the following steps: S1, bonding a glass carrier to the front side of the wafer after the front side front-end process is completed by adhesive, and then thinning the back side of the wafer by grinding / etching, and completing the back side front-end process of the wafer; S2, spray deionized water on the back of the wafer to form a water film of uniform thickness, then attach a silicon carrier to the back of the wafer, and use the attraction between water molecules and the external atmospheric pressure to make the silicon carrier and the wafer adsorb, then flip the glass carrier, wafer and silicon carrier as a whole, apply SOG at at least two points on the edge of the wafer for positioning, and finally debond and remove the glass carrier; S3, sending the silicon carrier and the wafer to a constant temperature drying device for baking, so that the water film between the silicon carrier and the wafer evaporates, and then using a spin coating medium SOG or polyimide to seal the edge of the wafer, and then using an organic solvent to dissolve and remove the adhesive, completing the wafer front end back-end process; S4, coating polyimide on the front side of the wafer to flatten the front side, then attaching a flat carrier to the front side of the wafer, extracting air through the exhaust holes of the flat carrier to make the wafer and the flat carrier adsorbed, then turning over the silicon carrier, the wafer and the flat carrier as a whole, cutting the silicon carrier and the wafer edge by laser to disconnect the blocking layer, release the bond between the silicon carrier and the wafer, and then lift and remove the silicon carrier; S5. Carrying the wafer on a flat carrier plate completes subsequent wafer processing.

2. The use of the planar carrier according to claim 1 in wafer loading, characterized in that: The front-end process in step S1 is all processes before the metal process on the front side of the wafer, including the ILD process and the contact hole opening process.

3. The use of the planar carrier according to claim 1 in wafer loading, characterized in that: The back side front-end process in step S1 includes all processes before the back side process of the wafer, including ion implantation.

4. The use of the planar carrier according to claim 1 in wafer loading, characterized in that: The front back-end process in step S3 includes a front metal process.

5. The use of the planar carrier according to claim 1 in wafer loading, characterized in that: The step S4 can also be to coat polyimide on the front side of the wafer to flatten the front side, then cut the sealing layer by laser cutting the silicon carrier and the edge of the wafer, attach the front side of the wafer to a flat carrier, and draw air through the exhaust holes of the flat carrier to adsorb the wafer and the flat carrier, then flip the silicon carrier, wafer and flat carrier as a whole, and finally lift and remove the silicon carrier.

6. The use of the planar carrier according to claim 1 in wafer loading, characterized in that: The subsequent wafer processes in step S5 include a wafer backside metal process, a yellow light process, and a wafer cutting process.

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