JP3813313B2 - Plasma surface treatment equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a plasma surface treatment apparatus that performs various treatments using plasma such as film formation, etching, and cleaning on the surface of a semiconductor chip, small mechanical electrical component, and the like.
[0002]
[Prior art]
Plasma is used to deposit and stack conductor layers and insulating layers on the surface of semiconductor substrates, small mechanical electrical components, optical plastic components, etc., and conversely to etch the surfaces of semiconductor substrates and laminates. Processing is now very widespread. In recent years, a dry cleaning process using plasma has been widely used for cleaning for removing dirt on the surface of a substrate or the like instead of a conventional wet process using chlorofluorocarbon.
[0003]
A conventional plasma surface treatment apparatus generally has a structure in which a sample mounting table is disposed below the reaction chamber, and a plate-like electrode is disposed on the upper side so as to face the sample mounting table. After placing the sample on the sample mounting table and introducing a reaction gas at a predetermined pressure into the vacuum reaction chamber, when high-frequency power is applied from the upper plate electrode, the grounded sample mounting table and the upper electrode Discharge occurs between them, and a plasma of a reactive gas is generated between both electrodes. Film formation is performed by exposing the sample on the sample mounting table to this plasma, and etching and cleaning are performed by ions and radicals strongly colliding with the sample surface.
[0004]
[Problems to be solved by the invention]
Semiconductor chips are processed only on one surface of a silicon wafer, such as film formation and etching. For example, a seek head for a hard disk drive is a thin elastic metal plate (usually a stainless steel sheet with a thickness of about 0.1 mm). Is used) and a conductive film is laminated on both surfaces via an insulating sheet. In such a conventional plasma surface treatment apparatus, in such a case, after forming a film on one side, the processing apparatus is temporarily stopped, the sample is inverted, and film formation is performed again.
The present invention provides a plasma surface treatment apparatus capable of processing both surfaces at once in such a case.
[0005]
[Means for Solving the Problems]
A plasma surface treatment apparatus according to the present invention, which has been made to solve the above-described problems, includes a central electrode that is a flat conductor having an opening, and first and first electrodes disposed at a predetermined distance on both sides of the central electrode. 2 counter electrodes.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
A sample to be processed is fixed in the opening of the central electrode. The sample is based on a conductor or semiconductor and is electrically connected to the central electrode. The center electrode is grounded, and the first and second counter electrodes are each connected to a high frequency power source. After the processing chamber is once evacuated, the necessary processing gas is introduced into the processing chamber and adjusted to a predetermined pressure. Thereafter, when high-frequency power is applied to the first and second counter electrodes, plasma is generated between the first counter electrode and the sample, and between the second counter electrode and the sample, and the sample has ions and radicals from both sides. Upon irradiation, processing such as film formation, etching, and cleaning is performed.
[0007]
In the above description, the high-frequency plasma is used. However, since the present invention simply provides a method for generating plasma on the upper and lower surfaces of the sample, it can be applied to various plasma processing apparatuses such as DC plasma and microwave plasma. The same can be applied.
[0008]
【Example】
A plasma dry cleaner according to an embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the plasma dry cleaner 10 of the present embodiment includes a reaction chamber 11 having a rectangular parallelepiped shape and a control unit 12 provided in the same casing. A plurality of rails 13 for inserting a tray 20 described later are provided on both side surfaces of the inner wall of the reaction chamber 11, and four rows of bus bars 14 and 15 are provided on the rear surface of the inner wall. The four rows of bus bars 14 and 15 have the high frequency side 14 at the center and the ground side 15 at the outer two rows, and each bus bar 14 and 15 has a tray at a position corresponding to the height of the rail 13. Insertion openings 141 and 151 (FIG. 2) for inserting terminals are provided. In each of the insertion ports 141 and 151, an elastic holding means is provided in order to ensure contact when a tray-side terminal described later is inserted.
[0009]
The control unit 12 includes a high frequency unit for supplying high frequency power for plasma generation (usually 13.56 MHz) to the high frequency side terminal and a control circuit for controlling the operation of the entire cleaner.
[0010]
The tray 20 charged into the reaction chamber 11 is provided with a plurality of types having different structures and functions. First, the high frequency side tray 21 and the ground side tray 22 are classified according to the polarity of the electrode used. As shown in FIGS. 2 (a) and 2 (b), both have the same overall size, and both can be inserted into the rails 13 of any stage of the reaction chamber 11 without distinction. The protruding positions of the provided terminals 24 and 25 are different. That is, the terminal 24 of the high frequency side tray 21 is provided closer to the center so as to match the insertion port 141 of the high frequency side bus bar 14, and the terminal 25 of the ground side tray 22 matches the insertion port 151 of the ground side bus bar 15. So that it is provided closer to the outside. Therefore, when the high frequency side tray 21 is pushed along the rail 13 of the reaction chamber 11, the terminal 24 of the tray 21 always enters the insertion port 141 of the high frequency side bus bar 14 and never enters the insertion port 151 of the ground side bus bar 15. There is no. On the contrary, when the grounding side tray 22 is inserted, the terminal 25 always enters the insertion port 151 of the grounding side bus bar 15 and never enters the insertion port 141 of the high frequency side bus bar 14.
[0011]
Since the housing of the reaction chamber 11 is grounded, the high frequency side tray 21 includes a frame 211 that contacts the rail 13 and a cleaning object mounting plate 213 that is fixed inside the frame 211 via an insulating member 212. (FIG. 2A). This cleaning object mounting plate 213 serves as a high frequency side electrode for plasma generation, and a tray terminal 24 inserted into the high frequency side bus bar 14 protrudes rearward from the cleaning object mounting plate 213. The ground side tray 22 does not need to be electrically floated, and can be formed of an electrically integrated metal body (FIG. 2B).
[0012]
The tray is divided into a simple flat plate-shaped tray, a grid-shaped tray, and an opening tray having an opening in the center in terms of shape.
[0013]
Various types of articles can be cleaned in various modes by appropriately combining these various trays. Here, a double-sided cleaning mode using an open tray will be described.
[0014]
As shown in FIG. 3B, the grounding side trays 41 and 43 are arranged above and below, an opening tray 42 with a high frequency side is inserted between them, and a metal-based object to be cleaned 422 is placed in the opening 421. Put. An example of the metal-based object to be cleaned 422 is a seek head for a hard disk drive. This has a structure in which a thin sheet 426 made of stainless steel is used as a base, and electrode layers 428 are formed on both sides thereof via a polyimide film 427. A sheet in which a number of seek heads are two-dimensionally arranged is placed in the opening 421 of the opening tray 42, and the stainless steel sheet 426 serving as a base and the opening tray 42 are electrically connected.
[0015]
Thus, the opening tray 42 in which the object 422 is fixed to the opening 421 is inserted into the reaction chamber 11 along the rail 13, and the terminal 424 of the tray 42 is inserted into the insertion port 141 of the high frequency side bus bar 14. After closing the door of the reaction chamber 11 and evacuating the interior, a cleaning gas such as argon Ar or nitrogen N2 is introduced into the reaction chamber 11 until a predetermined pressure is reached. When high frequency power of 13.56 MHz is applied to the opening tray 42 via the high frequency side bus bar 14, discharge occurs between the upper and lower ground side trays 41 and 43 and the object to be cleaned 422, and cleaning is performed on both surfaces of the object to be cleaned 422. A gas plasma is generated. These are irradiated from the upper and lower surfaces to the surface of the object to be cleaned 422, and the surface of the object to be cleaned 422 is physically and chemically removed. As described above, in the plasma dry cleaner of this embodiment, both surfaces are cleaned all at once. Therefore, in consideration of the time for evacuation or the like for replacing the object to be cleaned 422, each surface is cleaned one by one as in the prior art. The cleaning time can be reduced to half or less.
[0016]
Here, the example of the cleaning apparatus has been described. However, the present invention is not limited to cleaning of semiconductors and optical lenses, but the formation of a conductive layer or an insulating layer on a semiconductor chip and the pattern etching during semiconductor manufacturing. The present invention can be applied to any conventional plasma surface treatment apparatus such as micromachining by a strong etching action. As can be easily understood by those skilled in the art, the present invention merely provides a method for generating plasma on the upper and lower surfaces of a sample. It can be applied to various plasma processing apparatuses such as plasma.
[0017]
【The invention's effect】
Since the plasma surface treatment apparatus according to the present invention can perform both-side processing at the same time, the processing time can be reduced to at least half as compared with the conventional case where the processing is performed on each side. Further, in the case of performing a manual operation in which processing is performed by breaking the vacuum once, inverting the object to be processed, and performing evacuation again after processing one side, the effect of reducing the processing time becomes greater. Of course, it is possible to automatically perform such a reversing operation with a manipulator or the like without breaking the vacuum. However, since the cost of the apparatus greatly increases and the reversing time must be taken into consideration, the present invention Such devices still have a significant advantage.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional perspective view of a plasma dry cleaner according to an embodiment of the present invention.
FIG. 2 is a perspective view showing a relationship between a high frequency side tray (a) and a ground side tray (b) and a bus bar.
FIG. 3 is a perspective view (a) of an open tray and a sectional view (b) of a reaction chamber in use.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Plasma dry cleaner 11 ... Reaction chamber 12 ... Control part 13 ... Rail 20, 21, 22, 41, 43 ... Tray 42 ... Opening tray 421 ... Opening part 424 ... Terminal 422 ... To-be-cleaned object (seek head for hard disk drive)
426 ... Stainless steel base sheet 427 ... Polyimide film 428 ... Electrode layer

Claims (5)

a) a ground-side bus bar and a power-side bus bar each having a plurality of insertion openings provided in the housing;
b) a ground side tray having a terminal corresponding to the insertion port of the ground side bus bar;
c) a power supply side tray having a terminal corresponding to the insertion slot of the power supply side bus bar;
d) a power supply connected to the power bus bar;
A plasma surface treatment apparatus comprising:   The plasma surface treatment apparatus according to claim 1, wherein the power source is one of a high frequency power source and a direct current power source.   The surface treatment apparatus according to claim 1, wherein the power supply side tray has a simple flat plate shape.   The surface treatment apparatus according to claim 1, wherein the power supply side tray has an opening for arranging a material to be treated in the center.   The surface treatment apparatus according to claim 1, wherein the power supply side tray has a grid shape.

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