| 학회 | 한국재료학회 |
| 학술대회 | 2012년 가을 (11/07 ~ 11/09, 라카이샌드파인 리조트) |
| 권호 | 18권 2호 |
| 발표분야 | A. 전자/반도체 재료(Electronic and Semiconductor Materials) |
| 제목 | Study of Slurry pH and oxidizer on Ge-doped SbTe film in PRAM CMP |
| 초록 | As the design rule of memory devices has been shrink down, pattern structure of these devices and the metallization used to form them have become more and more complicated. Chemical mechanical polishing (CMP) is an essential process for manufacturing of the phase change random access memory (PRAM) device below 30 nm design rule to achieve flat surface and separate phase change material such as Ge-doped SbTe (Ge-ST). To avoid dishing of Ge-ST, erosion of SiO2 as dielectric in confined pattern structure. Ge-ST CMP requires a high polishing rate selectivity of Ge-ST to SiO2 film. We investigated the effect of pH in slurry on etch rate of Ge-ST film. The electrostatic interactions between the slurry abrasives and film surface are important during CMP and these electrostatic interactions are strongly influenced by the pH of the slurry. To investigate the chemical action of Ge-ST film during CMP, we conducted wet-etching test of Ge-ST film in slurry at acidic (pH ~2), near neutral (pH ~8), alkaline (pH ~10) conditions without and with H2O2. In addition, we analyze change of Ge-ST film surface measured by X-ray Photoelectric Spectroscopy (XPS). Then, we carried out CMP test with slurry at various pH without and with H2O2. It was found that the corrosion pit was decreased as slurry pH decreased. In addition, H2O2 react with surface of Ge-ST film, and prevent corrosion induced pits. In addition, most adsorption compounds were removed at pH 4 to pH 8. Acknowledgments This investigation was financially supported by the Brain Korea 21 Project in 2012. Also, this work was supported by the IT R&D program of MKE/KEIT. [KI002189, Technology Development of 30 nm level High Density Perpendicular STT-MRAM]. We thank SK Hynix Inc. and Sumco Corp. for helping with the experiments. Keywords: PRAM, Ge-ST, CMP, Defect |
| 저자 | Soo-Beom Kima1, Jong-Young Cho2, Jae-Hyung Lima3, Hee-Sub Hwang4, Jin-Hyung Park1, Eung-rim Hwang2, Jea-Gun Park3 |
| 소속 | 1Advanced Semiconductor Material & Device Development Center, 2Hanyang Univ., 3Seoul 133-791, 4Korea |
| 키워드 | CMP; PRAM |
