JPS6342369A - Sputtering treatment device - Google Patents

Abstract

PURPOSE:To prevent the remaining of air bubbles on the rear side of a backing plate for supporting a water cooled lower electrode and to improve cooling efficiency by forming backing plate to such a thickness that the rear side thereof is thinner in the central part and thicker toward the circumference and draining water near the central part. CONSTITUTION:A thin film is formed on a substrate 8 by regulating the reactive gas in a hermetic vessel 1, impressing a voltage to an upper electrode (substrate holding body) 7 and lower electrode (target) 3 and sputtering the target 3. A double pipe cooling structure 23 is internally provided between the backing plate 21 for holding the target 3 and a target support 22. The backing plate 21 is formed to the thickness of the tapered shape on the rear side with which the plate is thinner in the central part and thicker toward the circumference. The cooling water is introduced from the circumference of the backing plate 21 into the double pipe cooling structure 23 with its outside pipe as an inflow port 23a and is discharged from the inside pipe near the central as a discharge port 23b. The air bubbles in the cooling water are thereby collected at the central part and are easily discharged. The target 3 is thus efficiently cooled.

Description

[Detailed Description of the Invention] [Summary] The present invention provides a parallel plate type thin film forming sputtering apparatus,
Alternatively, the thickness of the backing plate that cools and supports the target or the lower electrode consisting of the substrate support in sputter processing equipment such as sputter etching equipment is made into an inclined shape that is thinner in the center on the back side and thicker toward the periphery. Cooling water flows into the back surface area of the banking plate from around the back surface toward the center, and a cooling water outlet is arranged close to the center at a higher position than the inlet. By removing air bubbles that collect at the center of the back surface of the backing plate together with water from the discharge port, the reduction in cooling efficiency of the lower electrode caused by residual air bubbles is eliminated and the cooling effect is improved. .

[Industrial application field]

The present invention relates to a parallel plate type thin film forming sputtering apparatus,
The present invention also relates to sputter processing apparatuses such as sputter etching apparatuses, and particularly to improvements in the cooling structure of electrodes to be cooled in these apparatuses.

In parallel plate type sputtering equipment for thin film formation or sputter etching equipment for thin film processing, as the demand for thin film use has expanded in recent years, the thin film forming area or thin film etching area has increased, or the thin film forming or thin film etching As machining speeds have increased, large amounts of power have been used and target areas have increased. For this reason, for example, in sputtering equipment, there is a strong demand to improve the cooling effect of the target, which causes a noticeable temperature rise, and in sputter etching equipment, it is strongly desired to improve the cooling effect of the electrode, which is used to hold a substrate that has a thin film to be etched, and which causes a rise in temperature. .

[Conventional technology]

As shown in FIG. 2, the conventional sputtering apparatus for thin film formation, for example, of the parallel plate type described above, has a target (lower part A banking plate 5 with electrodes 3 attached thereto, a target support 4 incorporating a double tube cooling structure 6, and a substrate 8 on which a thin film is to be formed opposite thereto.
An upper electrode 7 is disposed on the substrate holder holding the substrate.

Further, shield members 9 and 10 are arranged around the target support 4 and the substrate holder 7.

In order to form a thin film on the substrate 8 held by the substrate holder 7 using such a sputtering apparatus, first, the inside of the airtight container 1 is evacuated, and then the reaction gas inlet 1 is evacuated.
For example, argon (Ar) gas is flowed into the airtight container 1 from the container 1, and the Ar gas pressure in the airtight container 1 is adjusted to a constant value while balancing the exhaust volume and the flow rate of the Ar gas. After that, cooling water is flowed into the double tube cooling structure 6 as shown by the arrow to cool the target 3 which generates heat due to the collision of static ions, and a high voltage of 1 to 4 KV is applied to the target 3 from the power source. Generates a glow discharge to ionize static gas.

The ^r ions are accelerated in the direction of the target 3 and collide with the target 3 surface, and at this time, fine particles made of molecules or atoms are ejected from the target 3 surface and are deposited on the opposing substrate 8 surface, forming a thin film. is formed.

[Problem that the invention seeks to solve]

By the way, when high power is applied to such a conventional sputtering apparatus or a magnet is introduced into the target 3 arrangement part to speed up thin film formation, the target 3 is rapidly consumed, and as a result, the target 3 is depleted. The frequency of replacement is also significant, making it complicated.

The target 3 is replaced with the backing plate 5 after the residual cooling water in the double tube cooling structure 6 built into the target support 4 is removed by high pressure air, etc. Cooling water flows into the double pipe cooling structure 6 to cool the target 3 via the banking plate 5.

However, in the conventional double-pipe cooling structure 6, since the cooling water outlet 6b in the back surface area of the backing plate 5 is located at a lower position than the inlet 6a, the backing plate 5, which should be filled with cooling water, is The air in the back area cannot be completely replaced with cooling water and remains as bubbles.

For this reason, there is a drawback that the backing plate 5 and the target 3 cooled through the backing plate 5 are insufficiently cooled due to the residual air bubbles.

Insufficient cooling of the target 3 not only discolors the surface of the target 3 and reduces the film formation rate, but also poses a problem of hindering the formation of a good thin film.

In view of the above-mentioned conventional drawbacks, the present invention improves the shape of the back surface of the backing plate on which the target is attached and the positional relationship between the cooling water inlet and outlet in the double-pipe cooling structure. Provided is a new parallel plate type thin film forming sputtering device, that is, a sputter processing device, which completely replaces the air that tends to remain in the back surface area with cooling water, thereby eliminating the reduction in target cooling effect caused by residual air (bubbles). The purpose is to

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a pair of parallel plate-type upper electrodes and a water-cooled lower electrode, which are arranged horizontally opposite to each other at a predetermined interval in an airtight container. The thickness of the backing plate that supports the lower electrode is made into an inclined shape that is thinner at the center and thicker toward the periphery on the back side, and cooling water is applied to the back side of the banking plate. A cooling structure is adopted in which water flows from the periphery of the back surface toward the center, and drains water downward from a discharge pipe port located close to the center and located at a higher position than the inlet.

[For production]

In the sputter processing apparatus comprising a parallel plate type sputtering apparatus for thin film formation of the present invention, the thickness of the backing plate supporting the lower electrode is made into an inclined shape on the back side, which is thinner at the center and thicker toward the periphery. Cooling water flows into the back surface area of the backing plate from around the back surface toward the center, and flows downward from the discharge pipe port located close to the center, which is located higher than the inlet. Since the air bubbles remaining on the back surface area of the backing plate inevitably collect in the center of the back surface area, they are easily discharged together with water from the discharge pipe port located close to each other by water flow or water pressure. Ru.

Therefore, the problem that the cooling of the backing plate supporting the lower electrode is hindered by residual air bubbles is resolved, and the cooling efficiency is improved.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic sectional view showing an example in which the structure of an embodiment of the sputter processing apparatus according to the present invention is used in a parallel plate type thin film forming sputtering apparatus.

In the figure, 1 is an airtight container connected to an exhaust pipe 2 connected to a summer air exhaust system (not shown), and 21 is a target.
A backing plate that holds the (lower electrode) 3, 22 is a target support having a double tube cooling structure 23 therein, and 7 holds a substrate 8 on which a thin film is to be formed facing the target (lower electrode) 3. Substrate holder (upper electrode)
It is.

The backing plate 21 has an inclined shape in which the thickness is thinner at the center on the back side and thicker toward the periphery.
For the back surface area of the backing plate, the double pipe cooling structure 23 includes an inlet 23a through which cooling water flows from the periphery of the back surface of the banking plate 21 toward the center as shown by the arrow; The water is drained downward through a discharge port 23b located close to the central portion and located at a higher position than the discharge port 23a.

Therefore, the air bubbles remaining in the back surface area of the backing plate 21 will inevitably gather in the center of the back surface area unless the device is tilted beyond the permissible range, and will be removed by water flow, water pressure, etc. Discharge ports 3 placed close together
It becomes possible to easily discharge water from 2b together with waste water.

As a result, the target (lower electrode) 3 is cooled extremely efficiently via the backing plate 21, and discoloration of the target (lower electrode) 3 surface, reduction in film formation rate, and abnormal thin film formation are eliminated. Ru.

In the above embodiments, an example was explained in which a parallel plate type thin film forming sputtering apparatus was used as the sputter processing apparatus, but the essence of the present invention is not limited to this example. Needless to say, the present invention can also be applied to a water-cooled cooling structure built into a lower electrode that holds a thin film forming substrate in a flat plate type thin film processing sputter etching apparatus, dry etching apparatus, etc., and similar effects can be obtained.

〔Effect of the invention〕

As is clear from the above description, according to the sputter processing apparatus according to the present invention, the cooling water contact area of the backing plate g surface that holds the film forming target (lower electrode) or the lower electrode for holding the thin film forming substrate. This has the advantage that air bubbles remaining in the lower electrode can be easily removed together with drainage, and the cooling effect of the lower electrode is always maximized. Therefore, it is extremely advantageous as it can be used in this type of sputter processing apparatus.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view showing an example of the structure of an embodiment of a sputter processing apparatus according to the present invention used in a parallel plate type thin film forming sputtering apparatus. FIG. 2 is a schematic cross-sectional view for explaining a flat plate type thin film forming sputtering apparatus as an example. In FIG. 1, 1 is an airtight container, 3 is a target (lower electrode), 7 is a substrate holder (upper electrode), 8 is a substrate, and 21
is a backing plate, 22 is a target support, 23
23a is a double pipe cooling structure, 23a is an inlet, 23b is an outlet, and 23b is an outlet.
mFigure 1

Claims (1)

[Claims] A pair of electrodes (3, 7) consisting of an upper electrode (7) and a lower electrode (3) cooled by water are arranged horizontally opposite each other at a predetermined distance in an airtight container (1). In an apparatus configuration in which the surface of the lower electrode (3) is sputtered in a sputtering gas atmosphere, a backing plate (21) that supports the lower electrode (3) cooled by water;
The thickness of the backing plate (21) is thinner at the center and thicker toward the periphery on the back surface side, and cooling water flows from around the back surface of the backing plate (21) toward the center, and a discharge port is disposed close to the center. (23b) A sputtering treatment apparatus characterized in that the water is drained more quickly.