| 학회 | 한국재료학회 |
| 학술대회 | 2012년 가을 (11/07 ~ 11/09, 라카이샌드파인 리조트) |
| 권호 | 18권 2호 |
| 발표분야 | A. 전자/반도체 재료(Electronic and Semiconductor Materials) |
| 제목 | Role of H2O2 as oxidizer on the Ge-doped SbTe film for Chemical Mechanical polishing |
| 초록 | The Phase-change random-access memory (PRAM) has been investigated as one possible substitution of next generation nonvolatile memory because of its high scalability, fast operation speed and good endurance as compared with conventional Flash memory. In spite of its many advantages, there are some problems such as high reset current, cross talk as the thermal stability in order to scale down below the 10nm design rule. To solve these problems, phase change materials have to change to binary alloy from ternary alloy, and Contact area between electrode and Ge2Sb2Te5 (GST) has to be minimized. To satisfy these conditions, Ge-doped SbTe (Ge-ST) films have been used and investigated. From previous experiment of indentation test, Ge-ST film is softer than GST film. This weakness causes various issues for CMP process which is essential to achieve confined cell structure in PRAM devices. The representatives of these various issues are corrosion pits, unwanted high polishing rate accelerated by etch rate and defect generation in the pattern hole structure. To solve these technical hurdles, we carried out etching test using various oxidizers. We found that H2O2 is effective to inhibit corrosion, and corrosion-pit generation. Applying H2O2 with varied concentration, CMP performance was evaluated. We found that unwanted Polishing rate of Ge-ST was considerably decreases, Corrosion pits decrease, and defect generation in the pattern film decreases. These results are mainly due to the chemical-passive layer formed by H2O2 on Ge-ST film. We concluded that the slurry which is containing 5wt% H2O2 is moderate, in terms of polishing rate of Ge-ST, polishing selectivity of Ge-ST to SiO2, generation of corrosion pits, and defects in the pattern film. Acknowledgments This investigation was financially supported by the Brain Korea 21 Project in 2012. Also, this work was supported by the ITR&Dprogram of MKE/KEIT. [KI002189, Technology Development of 30nm level High Density Perpendicular STT-MRAM]. We thank Hynix Semiconductor Inc. and Sumco Corp. for helping with the experiments. |
| 저자 | Sang-Hwa Woo1, Jea-Gun Park2, Jong-Young Cho3, Hao Cui4, Eung-Rim Hwang1, Jin-Hyung Park2 |
| 소속 | 1Advanced Semiconductor Material & Device Development Center, 2Hanyang Univ., 3Seoul 133-791, 4Korea |
| 키워드 | PRAM; Ge-ST; CMP; Corrosion; Polishing Rate |
