Surface treatment process of CMP Polishing pad

Abstract

A surface treatment process of a CMP (chemical mechanical polishing) polishing pad includes steps of rough-machining, fine-machining and finish-machining a substrate in sequence with an abrasive belt with a particle size of 120-mesh, an abrasive belt with a particle size of 240-mesh and an abrasive belt with a particle size of 400-mesh, respectively till a target thickness of the substrate is obtained. In each processing stage, the surface of the substrate is sanded through effectively adjusting the height of the corresponding abrasive belt so as to effectively control a surface roughness of the substrate. Moreover, through the surface treatment process provided by the present invention, the initial surface roughness is consistent with the surface roughness in the usage process of the substrate, so as to solve the problem that the initial grinding rate is unstable, thereby significantly improving the stability of the substrate in the CMP process.

What is claimed is: 
     
         1 . A surface treatment process of a CMP (chemical mechanical polishing) polishing pad, comprising steps of:
 (S1) determining a final target thickness of a substrate to be D mm;   (S2) rough-machining the substrate, which comprises selecting a first abrasive belt with a particle size of 120-mesh, placing the substrate in a sanding machine, sanding the substrate in an alternating manner of a front surface and a reverse surface of the substrate, adjusting a height of the first abrasive belt for several times while changing the front surface and the reverse surface of the substrate till the thickness of the substrate is D+(0.08-0.10) mm;   (S3) fine-machining the substrate, which comprises selecting a second abrasive belt with a particle size of 240-mesh, placing the substrate below the second abrasive belt, sanding the substrate in the alternating manner of the front surface and the reverse surface of the substrate, adjusting a height of the second abrasive belt for several times while changing the front surface and the reverse surface of the substrate till the thickness of the substrate is D+(0.01-0.02) mm; and   (S4) finish-machining the substrate, which comprises selecting a third abrasive belt with a particle size of 400-mesh, placing the substrate below the third abrasive belt, sanding the substrate in the alternating manner of the front surface and the reverse surface of the substrate, adjusting a height of the third abrasive belt for several times while changing the front surface and the reverse surface of the substrate till the thickness of the substrate reaches the final target thickness of D mm.   
     
     
         2 . The surface treatment process, as recited in  claim 1 , wherein in the step of (S2), an adjusted height of the first abrasive belt every time is not more than 0.09 mm. 
     
     
         3 . The surface treatment process, as recited in  claim 1 , wherein in the step of (S3), an adjusted height of the second abrasive belt every time is not more than 0.04 mm. 
     
     
         4 . The surface treatment process, as recited in  claim 1 , wherein in the step of (S4), an adjusted height of the third abrasive belt every time is not more than 0.02 mm.