Abstract: The present invention relates to a plasma etching method and a plasma etching apparatus, and more particularly to a plasma etching method and a plasma etching apparatus in which the selection ration is enhanced by improving trench side-wall protecting effect.

Abstract: In order to etch an object to be processed, such as a semiconductor wafer, the object to be processed is placed in a vacuum processing chamber, an etching gas is introduced into the vacuum processing chamber, and electrical power is applied to a pair of electrodes within the vacuum processing chamber by a high-frequency electrical power source. A mixed gas of carbon monoxide and a gas which does not contain hydrogen and which contains at least one element from the group IV elements and at least one element from group VII elements is used as the etching gas. A halogenated carbon gas, typically a fluorocarbon such as C.sub.4 F.sub.8, is used as the gas containing elements from the group IV and group VII elements. The concentration of carbon monoxide in the etching gas could be 50% or more. At least approximately 86% of an inert gas, such as argon, xenon, krypton, or N.sub.2 and O.sub.2 could be added to the etching gas.

Abstract: A vacuum chamber contains a first electrode for supporting a wafer, and a second electrode opposing the first electrode. A supply system and an exhaustion system are connected to the vacuum chamber. The system supplies a reactive gas into the chamber, and the system exhaust the used gas from the chamber. A radio-frequency power supply is connected to the first electrode, for supplying power between the electrodes to generate an electric field E. An annular magnet assembly is provided around the chamber, for generating a magnetic field B which has a central plane intersecting with the electric field E. The magnet assembly has a plurality of magnet elements which have different magnetization axes in the central plane of the magnetic field. Electrons drift due to a force resulting from an outer product (E.times.B) of the electric field E and the magnetic field B.

Abstract: An etching apparatus comprises a pair of electrodes provided to face each other in a processing vessel, a permanent magnet for forming a magnetic field substantially parallel to a surface of a to-be-processed object which is placed between the paired electrodes, a gas introduction section for introducing etching gas into the processing vessel, a high-frequency generator for applying high-frequency voltage to the paired electrodes for generating plasma, and a high-frequency control section for preventing plasma from being unevenly distributed by starting and stopping the application of high-frequency voltage by the high-frequency generator at fixed intervals.

Abstract: A plasma etching apparatus has a lower electrode for supporting a semiconductor wafer in a processing room, an upper electrode opposite to the lower electrode, and an RF power supply for applying an RF power across the upper and lower electrodes. An SiN layer as an underlayer having a shoulder portion, and an SiO.sub.2 layer covering the SiN layer are disposed on the wafer. A contact hole is formed in the SiO.sub.2 layer by etching so as to expose the shoulder portion of the SiN layer. A processing gas contains C.sub.4 F.sub.8 and CO. To set the etching selection ratio of SiO.sub.2 /SiN, the discharge duration of each part of the processing gas is used as a parameter. The progress of dissociation of C.sub.4 F.sub.8 is controlled by selecting the discharge duration. The discharge duration is determined by the residence time of each part of the processing gas and the application time of an RF power.