Entity

Time filter

Source Type


Zhang Z.,Chinese Academy of Sciences | Zhang Z.,University of Chinese Academy of Sciences | Zhang Z.,Shanghai Xinanna Electronic Science and Technology Co. | Liu W.,Chinese Academy of Sciences | And 5 more authors.
Journal of the Electrochemical Society | Year: 2010

Chemical mechanical polishing (CMP), as a widely used planarization technology, requires high removal rate and low surface roughness generally. However, it is difficult to meet these requirements in a single-step polishing process. To get an ultrasmooth surface of the sapphire substrate, we investigated a two-step CMP of the sapphire substrate using ultrafine α -alumina-based slurry and nanoscale silica-based slurry. Also, in situ coefficient of friction (COF) measurements were conducted. The results show that during the first-step polishing in the alumina-based slurry, the COF decreases with polishing time first and then tends to be a constant; a relatively high material removal rate was reached, and the root-mean-square (rms) roughness value of the polished surface can be decreased from 968.9-21.98 Å. In the second-step CMP, the nanoscale silica slurry was adopted; the COF increased in the first minute of polishing and then became stable too, and the rms roughness of the sapphire substrate surfaces can be further reduced to 6.83 Å by using the optimized process parameters. In addition, the CMP mechanism of sapphire using the above two slurries was deduced and documented preliminarily. © 2010 The Electrochemical Society. Source


Zhang Z.,CAS Shanghai Institute of Microsystem and Information Technology | Zhang Z.,Shanghai Xinanna Electronic Science and Technology Co. | Zhang Z.,University of Chinese Academy of Sciences | Liu W.,CAS Shanghai Institute of Microsystem and Information Technology | And 3 more authors.
ECS Transactions | Year: 2010

This study explores the effect of pH and abrasive concentration on the chemical mechanical polishing of blank Ge 2Sb 2Te 5 (GST) film using the colloidal silica-based slurry. High polishing rates were observed at low pH values and material removal rate (MRR) appears as a linear function of abrasive concentration. To better understand the effect of abrasive concentration on the material removal, MRR per abrasive particle was calculated and on-line coefficient of friction (COF) test was also conducted. Experimental results show that MRR per particle decreases along with abrasive concentration and COF increases linearly according to the abrasive concentration, which indicates that polishing efficiency per particles decreases linearly and MRR is strong related to COF respectively, during the CMP process. ©The Electrochemical Society. Source


Zhang Z.,CAS Shanghai Institute of Microsystem and Information Technology | Zhang Z.,Shanghai Xinanna Electronic Science and Technology Co. | Zhang Z.,University of Chinese Academy of Sciences | Yan W.,CAS Shanghai Institute of Microsystem and Information Technology | And 9 more authors.
Microelectronic Engineering | Year: 2011

The effect of mechanical process parameters such as down force and rotation speed on friction behavior and material removal rate (MRR) was investigated during chemical mechanical polishing (CMP) of sapphire substrate. It was found that the increase in both rotation speed and down force can enhance the MRR and friction force almost linearly depends on the down force and rotation speed. The coefficient of friction (COF) decreases with increasing rotation speed under a fixed down force but keeps constant regardless of variation in down force under a fixed rotation speed. Moreover, the relationship between friction force and MRR was obtained. MRR was proportional to friction force with increasing down force whereas converse proportional to that with increasing the rotation speed. In addition, MRR data are fitted to the Preston equation in the sapphire CMP. © 2011 Elsevier B.V. All rights reserved. Source

Discover hidden collaborations