Grinding process for back of wafer

Abstract

The wafer back side grinding process is one integrated semiconductor manufacture process capable of avoiding warping and damage of wafer and accurate positioning. The process includes the following steps: providing wafer with active side and back side, loading the wafer via adsorption onto the grinding plate to expose the back side of wafer, grinding the back side of wafer, adhering positioning part to the ground wafer back side, and unloading the wafer via eliminating the adsorption force of the grinding plate. During the step of adhering positioning part to the ground wafer back side, the adsorption force is maintained, and in the step of unloading the wafer the positioning part is used as carrier for shifting the wafer.

Description

technical field [0001] The invention belongs to semiconductor technology, in particular to a wafer back grinding technology. Background technique [0002] With the thinning trend of semiconductor package components, the chips in the package components also need to comply with thinner thickness. Therefore, a wafer backside grinding process is proposed. The conventional wafer back grinding process is implemented after the integrated circuit manufacturing process and before the wafer dicing process, so that multiple chips on the wafer can be thinned at one time. [0003] like figure 1 , figure 2 As shown, the traditional wafer back grinding process and wafer cutting process include the following steps: [0004] step one [0005] Provide wafer [0006] A wafer 20 having an active surface 21 for forming an integrated circuit and a corresponding back surface 22 is provided, and a protective tape 23 is usually pasted on the active surface 21 of the wafer 20 . [0007] step ...

AI Technical Summary

Problems solved by technology

Due to the known small size, such as 4in or 6in wafers, the wafer warpage (wafer war page) after back grinding is still not obvious, especially in the acceptable range, but as the wafer size increases, such as 6in Above, or the thickness of the grinding is more stringent, such as below 12 mils, such as figure 2 As shown, the warping of the wafer 20 after grinding is quite obvious, and the occurrence of this warping is more serious due to the residual stress of the wafer integrated circuit process and the thinning of the semiconductor base layer such as silicon, so that after the wafer is removed The wafer 20 is easily broken in the fourth step of the circle or in the subsequent handling steps.

[0026] The disclosed wafer dicing process is to pre-cut the wafer before grinding. The back of the wafer is pasted with the first tape. After the wafer is cut, the second tape is pasted on the active surface and the first tape is removed. After grinding, the wafer is formed into multiple wafers, and then the third tape is pasted on the back of multiple wafers after thinning and the second tape is removed. Therefore, the number of flipping and handling is quite frequent, and the alignment of wafers requires strict requirements. , In addition, when excessive grinding is required, the wafers that have been separated in the second tape may have displacement deviation or collision damage during grinding due to insufficient adhesion

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