Lower-extraction type etching device

Abstract

This invention relates to an etching device in the process of semiconductor wafers including a reacting chamber with an inlet and a pumping chamber with an air vent, in which, said pumping chamber is set under the reacting chamber connected with symmetrically arranged left ventilation channel and a right ventilation channel and said air vent and the inlet are at the same axes and arranged symmetrically, so the gas above the static chuck surface flows to either side symmetrically and realizes uniform pumping to the reacting chamber.

Description

technical field [0001] The invention relates to the technical field of microelectronics, in particular to an etching device in semiconductor wafer processing. Background technique [0002] Under low pressure, the reaction gas is excited by radio frequency power to generate ionization to form plasma. The plasma is composed of charged electrons and ions. Under the impact of electrons, the gas in the reaction chamber can not only transform into ions, but also absorb energy and form a large number of active groups. The active reactive groups react chemically with the surface of the etched substance and generate volatile reaction products. The reaction product breaks away from the surface of the material to be etched and is drawn out of the cavity by the vacuum system. A non-uniform gas distribution within the reaction chamber will result in large variations in etch rate and uniformity across the wafer surface inside the chamber. In a semiconductor fabrication plant, the proce...

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Problems solved by technology

Due to the influence of the molecular pump, the flow velocity is fast on the side near the exhaust port 4, and the gas density is small, and the flow velocity is slow on the side away from the exhaust port 4, and the gas density is relatively high. The distribution above the surface does not have axial symmetry, and changes greatly on the surface of the electrostatic chuck, resulting in a large difference in the chemical reaction speed between the formed reactive groups and the surface of the etched material, which eventually leads to the inhomogeneity of the etching rate

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