[7p-A402-1~6] 8.4 Plasma etching

△ [7p-A402-6] Improvement of Etching Process Distribution Controllability within a Wafer by Multi Gas Injection System

〇Isao Mori¹, Motohiro Tanaka¹, Tetsuo Kawanabe², Soichiro Eto², Naoki Yasui¹ (1.Hitachi High-Technologies Corp., 2.Hitachi, Ltd.)

Keywords:Plasma Etching Apparatus, Plasma Distribution Uniformity Control, Gas Velocity Distribution Control

In 10-nm logic semiconductor devices, it is required to process FinFETs which have high-aspect-ratio structures. To achieve a high yield in such a process, variation of CD (Critical Dimension) distribution across a wafer must be suppressed, and processes must be uniform at an atomic level. To meet these requirements, functions to control a distribution of plasma, ions, radicals and wafer temperature were developed. In this study, we developed multi gas injection system, which supplies gas into a chamber from multiple inlets to control a distribution of gas velocity. According to our experiment to investigate an effect of deposition gas on etch rate distribution, gas velocity distribution tuning with multi gas injection system can control the deposition rate distribution across a wafer from a center-high shape to a center-low shape. In addition, it is also confirmed with multiple OES (Optical Emission Spectroscopy) that the radical distribution is controlled. In our presentation, we will report the mechanism of controlling a radical distribution by gas velocity distribution control and its effect on an etch rate distribution.