HIGH ASPECT RATIO ETCH WITHOUT UPPER WIDENING

• Main Authors: CHIA-SHIUNG TSAI, CHUNG-YEN CHOU, RU-LIANG LEE, LEEUAN TSENG
• Format: Patent
• Language: Chinese; English
• Published: 09.11.2016
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICALDEVICES; MICROSTRUCTURAL TECHNOLOGY; PERFORMING OPERATIONS; PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTUREOR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS; SEMICONDUCTOR DEVICES; TRANSPORTING

An embodiment of the invention provides a method for performing a high aspect ratio etch. A semiconductor substrate is provided with a hard mask layer arranged over the semiconductor substrate. A first etch is performed into the hard mask layer to form a hard mask opening exposing the semiconductor substrate. The hard mask opening has a bottom width. A second etch is performed into the semiconductor substrate, through the hard mask opening, to form a substrate opening with a top width that is about equal to the bottom width of the hard mask opening. A protective layer is formed lining a sidewall of the substrate opening. A third etch is performed into the semiconductor substrate, through the hard mask opening, to increase a height of the substrate opening. The top width of the substrate opening remains substantially unchanged during the third etch. A semiconductor structure with a high aspect ratio opening is also provided. The embodiment of the invention relates to high aspect ratio etch without upper wideni