研磨製程對於藍寶石基板表面平坦度之改善

Abstract

為提高藍寶石基板加工品質，如何改善因藍寶石基板平坦度(Total thickness variation,TTV)不佳而導致圖案化藍寶石基板(Pattern Sapphire Substrate,PSS)製程之微影異常損失即為重要之課題。本研究利用改變研磨製程(Lapping process)中之壓力及研磨粉料進行品質最加化之實驗。 本研究共分為兩個部分，第一部分為使用相同的機台以及研磨粉料，更改研磨製程所施加之單位面積壓力，藉由實驗結果發現降低單位面積壓力進行研磨能得到較佳之TTV。第二部分則為使用相同的機台及壓力條件，將研磨粉料由碳化矽(SiC)更改為碳化硼(B4C)，發現碳化硼對於TTV之改善效果較碳化矽佳。分析實驗結果得知，粉料硬度較硬，且使用較輕之壓力，因粉料於研磨過程中不易破碎，為修整TTV較佳之條件。

The key issue in improving quality of Sapphire substrate processing is how to decrease the losses caused by Pattern Sapphire Substrate exposure defocus issue since the total thickness variation (TTV). This research is using the change of pressure and abrasive in Lapping process to find out the best conditions for raising quality of Pattern Sapphire Substrate. This research is divided into two parts. The hypothesis in the first part of the study is that under the condition of the same machine, the change of pressure will decide the TTV. The experimental results show that the TTV improved as pressure decreased. In the second part, the experiment conducted with an emphasis on the change of the abrasive. Under the same machine and pressure, the silicon carbide abrasive (SiC) will be changed into boron carbide (B4C) . The result of experiment indicates that the boron carbide (B4C) using as Lapping abrasive will get better TTV. These results imply that the best condition for improving TTV is to take boron carbide (B4C) as the material and reduce the pressure.