JPS6058794B2 - plasma processing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a plasma processing apparatus that improves processing quality and processing speed.

As shown in FIG. 1, a plasma processing apparatus is a plasma processing apparatus in which a pair of flat electrodes 4 and 5 are arranged parallel to each other inside a container 3 equipped with an exhaust means 1 and a gas introduction means 2. The inside of the container 3 is adjusted to a predetermined degree of vacuum by the means 1 and the gas introducing means 2, and then, for example, a high frequency power source 6 applies high frequency power to the electrode 4 to generate plasma between the two electrodes,
Sputter etching equipment or plasma etching equipment that etches the sample 7 placed on the electrode 4 or electrode 5, and sputter deposition that causes particles scattered by the sputtering to adhere to the substrate 8 provided on the other electrode 5. Refers to the device.

By the way, in such a plasma processing apparatus, the container 3
Electrons and ions in the plasma generated inside collide with the wall surface of the container, recombine on the wall surface, and disappear, resulting in a decrease in plasma density between the two electrodes and a decrease in the etching or sputtering rate.

Further, impurities are desorbed from the wall surface of the container due to the collision of electrons and ions with the wall surface of the container. As a result, sample contamination and membrane deterioration occur. Therefore, as shown by the broken line in FIG. 1, a method can be considered in which a single magnet 9 is placed so as to surround the space between the two electrodes, but in this method, the magnetic field of the magnet is Due to the influence (see magnetic flux line B in Figure 1), electrons and ions are concentrated near the axis of the container 3, and the second
As shown in the figure, the distribution of plasma density becomes higher near the axis.

As a result, the etching rate for parts other than the center of the sample 7 or the sample placed other than the center part of the electrode 4 becomes extremely slow, and the time affected by uneven processing depending on the location and residual gas in the container is prolonged. Processing quality also deteriorates. The present invention has been made in view of the above points, and provides a novel plasma processing apparatus in which a multipolar magnetic field generating means is provided on the wall surface of a container. FIG. 3 is a schematic diagram of a plasma etching apparatus showing an embodiment of the present invention, and the same numbers used in FIG. 1 indicate the same components.

In this embodiment, the container 3 has a cylindrical shape.

As shown in FIG. 4, around the side surface (side wall) of the container, there are, for example, four stages of pole pieces IOA, IOB, IOC, IO.
D, and cylindrical permanent magnets 11A, IIB, 1IC, and IID are fitted into each pole piece. Now, the magnetic field caused by such a magnet exists only near the wall surface (see HA, HB, HC, l-[D), and rapidly decreases toward the center. Therefore, among the electrons and ions in the plasma generated between the electrodes 4 and 5 in the container 3, those that diffuse toward the container wall are absorbed by the magnets 11A, 11B, 11C, and 11D provided on the wall. They are repelled by their respective magnetic fields HA, HB, HC, and HD. Therefore, the number of electrons and ions that collide with the wall surface is significantly reduced, and the number of recombinations is also significantly reduced. Therefore, when the plasma density between the two electrodes except near the wall is uniform and there is no magnet, as shown in FIG. It increases significantly compared to . Furthermore, since the number of electrons and ions that collide with the wall surface of the container is significantly reduced, the amount of impurities desorbed from the wall surface is significantly reduced. Therefore, as a result of these, the etching rate becomes uniformly high for all the samples 7, 7'', 7'', . . . , and the productivity and processing quality are significantly increased. Note that as the multipolar magnetic field generating means, an electromagnet may be used instead of a permanent magnet, and a rod-shaped one may be used instead of a cylindrical one. Moreover, if these are placed not only on the side surfaces of the container but also on the top and bottom surfaces, the effect will be even higher. Further, a DC power source may be arranged instead of the high frequency power source to apply DC power between the electrodes 4 and 5.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a conventional plasma processing device, FIG. 2 is a magnetic flux distribution diagram, FIG. 3 is a schematic diagram of a plasma etching device showing an embodiment of the present invention, and FIG. 4 is a partial configuration diagram. FIG. 5 is a magnetic flux distribution diagram. 1: Exhaust means, 2: Gas introduction means, 3: Container, 4, 5:
Flat electrode, 7: sample, 10A, 10B, 10C, 10
D: Pole piece, 11A, 11B, 11C, 11D:
permanent magnet.

Claims (1)

[Claims] 1 Inside a container equipped with exhaust means and gas introduction means,
In an apparatus in which a pair of flat electrodes are arranged parallel to each other, direct current or high frequency power is applied between the electrodes, and a sample placed on either one of the electrodes is etched.
A plasma processing apparatus characterized in that a multipolar magnetic field generating means for generating a magnetic field only in the vicinity of the wall surface is provided on the wall surface of the container.