Method for polishing silicon through hole wafer and polishing combination for the same

Abstract

The invention relates to a method for polishing silicon through hole wafer and a polishing combination for the same. The method comprises the following steps of: using the polishing combination consisting of organic alkali compound, oxidant selected from sodium chlorite and/or potassium bromate, multiple silicon dioxide ground particles and solvent to polish the surface of the silicon through hole wafer so as to remove silicon and conductive material on the silicon through hole wafer by a removal rate respectively. By the method, the silicon and the conductive material on the silicon through hole wafer can be polished with higher polishing rate so as to greatly reduce time cost required for polishing the silicon through hole wafer. The invention also relates to the polishing combination used in the method.

Description

technical field [0001] The invention relates to a polishing method, in particular to a polishing method for a through-silicon via (Through-Silicon Via, TSV) wafer. The invention also relates to the polishing composition used in carrying out the method. Background technique [0002] The original structure of TSV wafer 1 is as figure 1 As shown, it includes an integrated circuit layer 11, a silicon wafer layer 12 located on the integrated circuit layer 11, and a plurality of silicon wafer layers 12 that are substantially perpendicular to the surface 121 of the silicon wafer layer 12 and are embedded in the silicon wafer layer 12 and connected. to the conductive material 13 of the integrated circuit layer 11 . Generally speaking, the end face 131 of the conductive material 13 in the unpolished TSV wafer is separated from the surface 121 of the silicon wafer layer 12 by approximately hundreds of microns. [0003] The surface 121 will be polished in the manner of "rough polish...

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Problems solved by technology

[0009] The above-mentioned various polishing compositions are all suitable for polishing a single specific material such as silicon or conductive materials. If silicon and conductive materials are polished at the same time, it is easy to have a large difference in the removal rate of the two materials. And it is difficult to simultaneously increase the polishing rate of silicon and conductive materials by increasing the content of specific components in the polishing composition; for example, when increasing the concentration of ethylenediamine in the polishing composition, the removal rate of silicon increases. The magnitude of the increase clearly exceeds the removal rate of conductive materials, that is, the removal rate of silicon may exceed However, the removal rate of conductive material may be only about

[0010] Similarly, it is known that the commonly used oxidizing agent H 2 o 2 The presence in the polishing composition helps to polish conductive materials, but it is easy to oxidize silicon into hard silicon dioxide, so when H in the polishing composition 2 o 2 The removal rate of the conductive material will also increase when the content of the silicon increases, but the removal rate of the silicon will decrease rapidly

[0011] From this point of view, H 2 o 2 Not suitable as a component in polishing compositions that polish both silicon and conductive materials

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