Chemical mechanical planarization of amorphous Ge_2Sb_2Te_5 with a soft pad  

作　　者：何敖东 刘波 宋志棠 吕业刚 李俊焘 刘卫丽 封松林 吴关平 

机构地区：[1]Shanghai Key Laboratory of Nanofabrication Technology for Memory,Shanghai Institute of Micro-system and Information Technology,Chinese Academy of Sciences [2]University of Chinese Academy of Sciences [3]Semiconductor Manufacturing International Corporation

出　　处：《Journal of Semiconductors》2013年第7期170-174,共5页半导体学报（英文版）

基　　金：Project supported by the National Key Basic Research Program of China(Nos.2010CB934300,2011CBA00607,2011CB9328004);the National Integrated Circuit Research Program of China(No.2009ZX02023-003);the National Natural Science Foundation of China(Nos. 60906004,60906003,61006087,61076121,61176122,61106001);the Science and Technology Council of Shanghai(Nos.11DZ2261000,11OA1407800.12nm0503701);the Chinese Academy of Sciences(No.20110490761)

摘　　要：Chemical mechanical planarization（CMP） of amorphous Ge_2Sb_2Te_5（a-GST） is investigated using two typical soft pads（politex REG and AT） in acidic slurry.After CMP,it is found that the removal rate（RR） of a-GST increases with an increase of runs number for both pads.However,it achieves the higher RR and better surface quality of a-GST for an AT pad.The in-situ sheet resistance（R_s） measure shows the higher R_s of a-GST polishing can be gained after CMP using both pads and the high R_s is beneficial to lower the reset current for the PCM cells. In order to find the root cause of the different RR of a-GST polishing with different pads,the surface morphology and characteristics of both new and used pads are analyzed,it shows that the AT pad has smaller porosity size and more pore counts than that of the REG pad,and thus the AT pad can transport more fresh slurry to the reaction interface between the pad and a-GST,which results in the high RR of a-GST due to enhanced chemical reaction.Chemical mechanical planarization（CMP） of amorphous Ge_2Sb_2Te_5（a-GST） is investigated using two typical soft pads（politex REG and AT） in acidic slurry.After CMP,it is found that the removal rate（RR） of a-GST increases with an increase of runs number for both pads.However,it achieves the higher RR and better surface quality of a-GST for an AT pad.The in-situ sheet resistance（R_s） measure shows the higher R_s of a-GST polishing can be gained after CMP using both pads and the high R_s is beneficial to lower the reset current for the PCM cells. In order to find the root cause of the different RR of a-GST polishing with different pads,the surface morphology and characteristics of both new and used pads are analyzed,it shows that the AT pad has smaller porosity size and more pore counts than that of the REG pad,and thus the AT pad can transport more fresh slurry to the reaction interface between the pad and a-GST,which results in the high RR of a-GST due to enhanced chemical reaction.

关 键 词：POROSITY soft pad chemical mechanical planarization Ge2Sb2Te5 

分 类 号：TP333[自动化与计算机技术—计算机系统结构] TN305[自动化与计算机技术—计算机科学与技术]