JPH01188672A - Rf sputtering device - Google Patents

Abstract

PURPOSE:To reduce the amount of particles generated at the time of sputter etching by producing plasma between a cathode electrode and a lattice-like third electrode provided in a manner to be opposed to the above cathode electrode. CONSTITUTION:When a high-frequency(RF) electric field is impressed, plasma is produced between a cathode electrode 1 and a lattice-like third electrode opposed to the above cathode electrode 1. By means of this plasma, a semiconductor wafer 4 is etched. Subsequently, the greater part of the etched substance is passed through the above electrode 3 and allowed to adhere to an anode electrode 2. The resulting sticking matter is never sputtered out and, as a result, the generation of particles can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an RF sputtering apparatus having a sputter etching function.

2. Description of the Related Art A cross-sectional view of an RF sputter etching electrode portion disposed in a container of a conventional aluminum sputtering apparatus is shown in FIG.

In the figure, 1 is a cathode electrode, 2 is an anode electrode, and 4 is a semiconductor wafer attached to the cathode electrode 1. When an appropriate amount of inert gas is sealed between the cathode electrode 1 and the anode electrode 2 in the container and a radio frequency (RF) electric field is applied, plasma is generated between the cathode electrode 1 and the anode electrode 2, The ionized etching species collide with the semiconductor wafer 3, resulting in physical etching called sputter etching.

Problems to be Solved by the Invention When sputter etching is performed using a conventional aluminum sputtering device, the etched material adheres to the anode electrode 2. What adheres to the anode electrode 2 is knocked out by the plasma, floats between the electrodes, or re-adheres to the semiconductor wafer 3 as foreign matter.

Originally, in an aluminum sputtering apparatus, sputter etching and aluminum deposition are performed continuously, so that foreign matter adhering to a semiconductor wafer is not removed and aluminum is deposited thereon. After that, when patterning is performed using photolithography technology, the part of the foreign substance causes a patterning failure, that is, holes are not made where they should have been made, causing short-circuit defects in the aluminum wiring, and the failure of semiconductor integrated circuit devices. This has the disadvantage of lowering yield.

When sputter etching is performed using a conventional aluminum sputtering device, several hundred particles of 0.3 μm or more are generated.

An object of the present invention is to provide an aluminum sputtering apparatus that makes it possible to reduce particles generated by sputter etching.

Means for Solving the Problems The aluminum sputtering apparatus of the present invention has a lattice-shaped third electrode as a sputter etching electrode in addition to an anode electrode and a cathode electrode.

According to this structure, plasma is generated between the cathode electrode and the third grid-shaped electrode facing it, and most of the sputter-etched material passes through the grid-shaped third electrode and attaches to the anode electrode. However, the attached particles will not be knocked out again, and particles can be reduced.

Example The present invention will be explained below with reference to FIG.

FIG. 1 is a cross-sectional view showing a sputter etching electrode portion arranged in a container of an aluminum sputtering apparatus of the present invention. 1 is a cathode electrode, 2 is an anode electrode, and 3
is a grid-like third electrode, and 4 is a semiconductor wafer to be etched.

With this structure, when an inert gas is sealed in the container and plasma is generated, the plasma is generated between the cathode electrode 1 and the grid-shaped third electrode 3 facing thereto. The semiconductor wafer 4 is etched by this plasma, and most of the etched material adheres to the anode electrode 2. Since plasma is generated between the cathode electrode 1 and the grid-shaped third electrode 3, the etched foreign matter is not knocked out again. Therefore, particles generated by sputter etching can be reduced.

When sputter etching is performed using the aluminum sputtering apparatus of the present invention, the number of particles above 0.3 μmJd can be suppressed to 50, which is about one-tenth of that of the conventional method.

Effects of the Invention According to the aluminum sputtering apparatus of the present invention, the number of particles generated by sputter etching a semiconductor wafer can be suppressed to about one-tenth of that of the conventional one, and as a result, the yield of semiconductor integrated circuit devices can be reduced. It has an extremely effective industrial effect that can improve the

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view of an aluminum sputtering apparatus according to the present invention, and FIG. 2 is a schematic sectional view of a conventional aluminum sputtering apparatus. 1... Cathode electrode, 2... Anode electrode, 3... Grid-like third electrode, 4...
・Semiconductor wafer.

Claims (1)

[Claims] An RF sputtering apparatus comprising an anode electrode, a cathode electrode, and a third electrode in the form of a grid, which opposes the anode electrode.