A pH-controlled chemical mechanical polishing method for thin bonded silicon-on-insulator wafers

• Published in: Japanese Journal of Applied Physics Vol. 34; no. 1; pp. 30 - 35
• Main Authors: SUGIMOTO, F, HORIE, H, ARIMOTO, Y, ITO, T
• Format: Journal Article
• Language: English
• Published: Tokyo Japanese journal of applied physics 1995
• Subjects: Applied sciences; Electronics; Exact sciences and technology; Microelectronic fabrication (materials and surfaces technology); Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Scanning electron microscopy; Mechanical polishing; Chemical polishing; Layer thickness; Silica; Thin film; Silicon on insulator technology; Microelectronic fabrication; Concentration effect; Groove; pH; Wafer; Uniformity
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/JJAP.34.30

A pH-controlled chemical mechanical polishing (CMP) method for fabricating largearea ultrathin silicon-on-insulator (SOI) layers with uniform thickness was developed. Using a polishing reagent with the pH and colloidal silica concentration lowered, together with grooves fabricated on the SOI layer to expose the insulating oxide, the polishing rate clearly decreased leaving a uniform 0.1-µ m-thick SOI layer. An SOI layer with superior thickness uniformity (±0.01 µ m) across 5-by-5-mm SOI-Si islands was obtained. The thickness uniformity across the wafers was decreased to ±0.07 µ m. In this technique, the end point for polishing was controlled to form thin SOI layers with uniform thickness.