JPH02137318A - Processing apparatus - Google Patents

Abstract

PURPOSE:To cope with processing conditions of semiconductor for manufacturing various types and to improve versatility by providing heating means and cooling means at predetermined positions of a medium circulating passage for setting a material to be processed to a predetermined temperature. CONSTITUTION:A lower electrode 15 is required to be regulated at its temperature corresponding to the type of a wafer to be processed, and regulated by circulating liquid regulated at its temperature in a passage 17 provided on the lower face of the electrode 15. The liquid discharged from the passage 17 is stored in a reservoir tank 25 through a pipe 18, and fed to the pipe 18 provided with a heating mechanism 28 or a cooling mechanism 30 by a pump 26. When the liquid is out of its set temperature, the cooling mechanism 30 and the heating mechanism 28 are switched to always maintain the liquid fed to the passage 17 at a set temperature, and to control the temperature of the electrode 15. Thus, it can cope with various types of processing conditions to be versatile.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a processing device.

(Conventional technology) In recent years, the complicated manufacturing process of semiconductor devices has been simplified.

Plasma etching equipment that utilizes reactive components in gas plasma is attracting attention as an etching equipment for various thin films that can automate processes and form fine patterns with high precision.

A plasma etching apparatus using this plasma is installed in an airtight container connected to, for example, a vacuum apparatus.

Electrode plates are arranged facing each other with a predetermined interval.

In addition, an RF power source is connected to one of these electrodes,
The other is grounded. For example, an object to be processed, such as a semiconductor wafer, can be placed on the ground electrode. Here, electric power is applied to the electrodes, and at the same time, a desired processing gas is supplied between the electrodes. Then, the processing gas is turned into plasma by the electric power, and the surface of the semiconductor wafer can be etched with the processing gas turned into plasma. However, when plasma etching is performed as described above, each electrode is heated by the plasma and the temperature rises. Also, 1! ! The temperature of the semiconductor wafer placed on top also rises. This poses a problem in that the photoresist formed on the wafer deteriorates, making it impossible to perform accurate etching. In order to solve this problem, techniques for cooling the electrode in order to suppress the rise in temperature of the electrode have been disclosed in Japanese Patent Publication No. 62-48758, Japanese Patent Application Laid-Open No. 10328-1982, Japanese Patent Application Laid-Open No. 8927-1987, etc. ing.

(Problems to be Solved by the Invention) However, the above conventional technology has the following problems.

For example, when performing plasma etching processing,
Processing conditions may vary depending on the type of semiconductor being manufactured. Some of them are during etching.

Plasma etching may be performed while circulating room temperature water or heated liquid within the electrode instead of circulating cooling water.

This poses a problem in that an apparatus equipped with only a cooling mechanism cannot perform processes compatible with various semiconductors.

Furthermore, if only a mechanism for circulating cooling water is used to cool the electrodes, there is a problem that the electrodes are cooled too much even when plasma etching is not being performed.

Therefore, by installing a heater, if the temperature became too cold than the set temperature, the heater would work to warm the temperature to the set temperature.

The present invention has been made in response to the above-mentioned problems, and provides a highly versatile processing apparatus that is compatible with the processing conditions of various types of semiconductors to be manufactured.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides a processing apparatus that processes an object to be processed at a predetermined temperature, in which a heating means and a cooling device are installed at a predetermined position in a medium circulation flow path in order to set the temperature. It is characterized in that each means is provided.

(Function and Effect) By providing heating means and cooling means respectively at predetermined positions in the medium circulation flow path to set the temperature, it is possible to correspond to the processing conditions of various semiconductors manufactured, and the versatility is improved. can get.

(Example) Hereinafter, one example in which the apparatus of the present invention is applied to etching processing of a semiconductor wafer will be described with reference to one drawing.

A reaction vessel made of a conductive material such as aluminum, the surface of which is alumite-treated, and configured to keep the interior airtight.
At the top of the inside, there is an electrode body (A) that can be raised and lowered via a lifting mechanism (for example, an air cylinder or ball screw) and a connecting rod.
is provided. This electrode body (a) is made of a conductive material, such as aluminum, and its surface is alumite-treated, and the electrode body (b) is equipped with a cooling means.

This cooling means 1, for example, forms a circulating flow path (C) inside the electrode body (A), and connects to the cooling means (2) provided outside the reaction vessel (2) via a pipe (Q) connected to this flow path (3). Continuously installed.

It has a structure in which a liquid such as water is controlled at a predetermined temperature and circulated.

An upper electrode (c) made of, for example, amorphous carbon is provided on the lower surface of such an electrode body (to) in electrical connection with the electrode body (a). Some space 0 is formed between this upper electrode (C) and the electrode body, and a gas supply pipe (10) is connected to this space 2.

This gas supply pipe (lO) is capable of freely supplying a reaction gas such as argon, freon, etc. from a gas supply source (not shown) inside and outside the reaction vessel to the space (2). This space 0
A plurality of holes (11) are formed in the upper electrode (to) so that the reaction gas supplied to the upper electrode flows into the reaction vessel through the upper electrode (to).

This upper electrode ■ and the electrode body) are surrounded by an insulating ring (
12), and a shield ring (13) extending from the lower surface of the insulating ring (12) to the peripheral edge of the lower surface of the upper electrode (2) is disposed. This shield ring (1
3) is made of an insulating material, such as tetrafluoroethylene resin, so as to be able to generate plasma to approximately the same size as the object to be etched, such as a semiconductor wafer (14). Further, the semiconductor wafer (14) has a lower portion 1't! provided at a position facing the upper electrode (toward). @(1
5) Can be set freely on the surface.

This lower electrode (15) is made of aluminum, for example, and has a flat plate shape with an alumite-treated surface. It slopes from the center to the periphery. A clamp ring (16) is arranged at the peripheral edge of the lower electrode (15), and the semiconductor wafer is held in such a way that the peripheral edge of the semiconductor wafer (14) is brought into contact with the R-shaped surface of the lower electrode (15). (14) is adapted to the caliber. This clamp ring (16) is made of aluminum, for example, and the surface is anodized, and the alumite treatment provides an insulating alumina coating on the surface. The semiconductor wafer (14) can be held at will. Also.

A lift pin (not shown) is provided near the center of the lower electrode (15), which allows the semiconductor wafer (I4) to be moved up and down during transportation. Yet again. This lower electrode (15) is provided with a plurality of holes (not shown), and the semiconductor wafer (14) is formed through the plurality of holes.
) Cooling gas such as helium gas can freely flow out. In addition, this lower electrode (15) includes a lower electrode (15).
A flow path (17) is provided in contact with the lower surface. This flow path (17) is connected to a temperature control mechanism (19) via piping (18).
is connected, and a temperature regulating body, such as a liquid, whose temperature is adjusted by a temperature regulating mechanism (19), is circulated.

Further, the upper electrode (2) is electrically connected to the RF electrode (20), and the lower electrode (15) is grounded. An exhaust ring (22) with an exhaust hole (21) is fitted in the gap from the side of the lower electrode (15) to the inner surface of the reaction vessel ω, and the reaction vessel below the exhaust ring (22) (g) Exhaust gas inside the reaction vessel (1) can be freely exhausted by an exhaust device (not shown) or the like via an exhaust pipe (23) connected to the side wall. In this way, the etching device (24) is constructed. Such an etching device (24) is
Operation and setting are controlled by a control section (not shown).

Next, a description will be given of the temperature control mechanism (19) that circulates the temperature-controlled liquid through the channel (17) provided on the lower surface of the lower mold tJn (15) described above.

As shown in FIG. 2, the flow path (1) on the bottom surface of the lower electrode (15)
7) is connected to two lines of piping (18), each serving as an inlet and an outlet for a liquid such as an ethylene glycol aqueous solution. A liquid outlet pipe (18) is connected to a reservoir tank (25) that temporarily stores the liquid. This reservoir tank (25) is connected to the liquid piping (18).
Piping (18) is connected to a pump (26) that supplies water to the water.

The pipe (18) from this pump (26) branches into two directions midway. One of the pipes (18a) is connected from one branch point to a heating mechanism (28) via a solenoid valve (27). The heating mechanism (28) has, for example, a resistance heating type heater (40) installed around the piping (18a).1 By applying electric power of, for example, 100V from a power supply (not shown), the heating mechanism (28) is heated into the piping (18a). It is used to heat the liquid that has been heated. Further, the other pipe (18b) is connected from the branch point to the cooling mechanism (30) via the solenoid valve (29).
is connected to. The cooling mechanism (30) is a pipe (tab)
For example, a coolant flow conduit (31) is provided around the pipe (18), and by flowing a coolant such as a long-life coolant aqueous solution into the coolant flow conduit (31), the pipe (18) is indirectly connected to the pipe (18).
b) It cools the liquid flowing into the tank. Here, a structure for flowing the coolant through the coolant flow conduit (31) will be explained. The coolant flow conduit (31) is arranged so that the coolant circulates between a coolant circulator (32) provided outside the etching device (24) and the periphery of the pipe (18b). Also, a flow switch (33) is provided at a predetermined location of this coolant flow conduit (31), for example after the coolant has passed through the cooling mechanism (30).

This flow switch (33) is connected to the coolant flow conduit (3).
1) This is to detect whether the flow rate of the coolant flowing inside is within a set value of 1 m.

When the cooling value deviates from the set value, the etching process is stopped to protect the lower electrode (15). This flow switch (33) is arranged vertically, for example, and allows the cooling liquid to be introduced into the interior from the lower inlet and discharged from the L-side outlet.

A float that is pushed up and floats by the flow of the cooling liquid is provided inside the flow switch (33). This float has a built-in magnet, and a reed switch is provided on the outer wall, so that when the float approaches, the reed switch is activated by the magnetic field of the magnet. When such a flow switch (33) is used, if the coolant contains dust, etc., the flow switch (33)
3) Dust and the like may adhere to the springs used inside, which may prevent the flow switch (33) from operating correctly. Correspondingly, the cooling liquid flow conduit (3
1) is provided with a flow meter (34).

This flow meter (34) is as shown in FIG.

A substantially spherical float (36) made of, for example, SUS (stainless steel) is provided within a tube (35) made of transparent glass. Further, a scale (37) indicating the flow rate is marked on the wall surface of the tube (35). The flow meter (34) is arranged vertically, and the cooling liquid is introduced from the lower inlet (38) and discharged from the upper outlet (39). J, the float (36) is pushed up and floated by the flow of the cooling liquid. This float (36
) and the displayed value on the scale (37) are read visually. By providing the flow switch (33) and flow meter (34) as described above, it is possible to check whether the coolant is accurately flowing in a predetermined amount within the coolant flow conduit (31). The cooling mechanism (30) is configured as described above.

Then, the piping (18a) from the heating mechanism (28) and the piping (18b) from the cooling mechanism (30) are merged into one again, and the piping (18) is connected to the lower electrode (15) as one piping (18). ) is connected to the flow path (17) on the bottom surface. In this way, the temperature control mechanism (19) is configured.

Next, the operation of the above-mentioned etching apparatus 1ft (24) will be explained.

First, an object to be processed, such as a semiconductor wafer (14), is loaded into the loading section (not shown) of one reaction vessel (2), and the object to be processed, such as a semiconductor wafer (14), is inserted into the center of the lower electrode (15) and placed in a lid bin (Fig. The semiconductor wafer (14) is lifted while the lift turbine (not shown) is raised, and the lift turbine is lowered to come into contact with the surface of the lower electrode (15).

Then, the peripheral edge of the semiconductor wafer (14) is pressed and held toward the lower electrode (15) by the clamp ring (16).

At this time, since the surface of the lower electrode (15) is formed to be somewhat rounded, even if the semiconductor wafer (14) has warpage caused by pre-processing, the lower ffi
The wafer contact surface can surely contact the pole (15) surface. Then, the inside of the reaction vessel (1) is kept airtight, and the inside is set to a desired vacuum state.

This vacuum operation may be performed in advance when the semiconductor wafer (14) is transferred, for example by using a preliminary chamber.

Next, the electrode body (A) is moved through the connecting rod ■ by the lifting mechanism ■.
is lowered, and the interval between the upper electrode (1) and the lower electrode (15) is set to a desired interval, for example, on the order of several meters. Then, a reaction gas such as argon gas is supplied from a gas supply source (not shown) to the space (2) through the gas supply pipe (10). The reaction gas supplied to this space flows out from a plurality of holes (11) provided in the upper electrode (1) to the surface of the semiconductor wafer (14). At the same time, high frequency power is applied between the upper electrode (1) and the lower electrode (15) by the RFIt source (20) to turn the reaction gas into plasma, and the semiconductor wafer (14) is etched by this plasmanized reaction gas. Let's do it.

At this time, the upper electrode (15) and the lower electrode (15) become hot due to the application of this high frequency power. When the upper electrode becomes hot, thermal expansion naturally occurs. In this case, the material of the upper electrode (2) is made of amorphous carbon, and the electrode body (A) in contact with it is made of aluminum, so the coefficients of thermal expansion are different and cracks occur. In order to prevent this crack from occurring, cooling water is flowed from the cooling means ■ connected to the flow path ■ formed inside the electrode body via piping 0, thereby indirectly cooling the upper electrode (c). are doing. Furthermore, the temperature of the lower electrode (15) also needs to be adjusted in accordance with the type of wafer to be processed. That is, cooling and temperature increase control, which is performed by circulating a temperature-controlled liquid through the flow path (17) provided on the lower surface of the lower electrode (15), is achieved by installing one or more sensors on the wafer. Automatic setting is possible by arranging them around the center and comparing the sensor output value with a predetermined temperature. Next, the circulation of this temperature control liquid will be explained.

The liquid discharged from the channel (17) passes through the pipe (18) and is temporarily stored in the reservoir tank (25). This stored liquid is heated by a heating mechanism (28) by a pump (26).
) or into a pipe (18) equipped with a cooling mechanism (30). Here, when flowing fluid to the heating mechanism (28),
The solenoid valve (27) provided in the pipe (18a) connected to the heating mechanism (28) is opened, and the solenoid valve (29) provided in the pipe (18b) connected to the cooling mechanism (30) is closed. shall be. The liquid then flows through the pipe (18a) to the heating mechanism (28). In the heating mechanism (28),
Electric power, for example, 100 V, is applied to the resistance heater in advance from a power source (not shown). The liquid is then heated.

This heated liquid is transferred from the heating mechanism (28) to the piping (1).
8) and is introduced into the flow path (17) on the lower surface of the lower electrode (15).

In addition, when flowing liquid from the pump (26) to the cooling mechanism (30), the solenoid valve (27) provided in the pipe (18a) connected to the heating mechanism (28) is closed, and the cooling mechanism (30) is closed.
Solenoid valve (2) installed in the pipe (tab) connected to
9) Open. The liquid then flows through the piping (18b) to the cooling mechanism (30). Cooling mechanism (30)
In this case, the coolant is circulated in advance through the coolant flow conduit (31) provided around the pipe (18b), and then the liquid flowing into the pipe (18b) is cooled. here.

The operation of flowing the coolant into the coolant flow conduit (31) will be explained.

The coolant cooled in the coolant circulator (32) passes around the piping (igb) by the coolant flow conduit (31) and is introduced into the flow switch (33). This flow switch (33) detects whether the flow rate of the flowing coolant is within a predetermined value. Upon this detection, if the coolant level is within a predetermined value, the etching process is continued; otherwise, the etching process is interrupted. After passing through this flow switch (33), the coolant is introduced into a flow meter (34). In this flow meter (34).

Since the flow switch (33) may malfunction, this is to allow the flow rate of the coolant to be visually checked at all times. Inlet (3) of flow meter (34)
The coolant introduced from 8) pushes against a float (36) provided in the pipe (35) and is discharged from the outlet (39). At this time, the flow rate of the coolant can be visually confirmed by the floating position of the float (36) and the scale (37). The coolant after passing through the flow meter (34).

The coolant flow conduit (31) again connects the coolant circulator (32).
be swept away by The liquid in the pipe (18b) cooled by such a cooling mechanism (30) is introduced into the flow path (17) on the lower surface of the lower electrode (15) through the pipe (18).

Here, if the temperature of the liquid flowing into the pipe (18) by the cooling mechanism (30) becomes too cold than the set temperature, the following operation occurs.

First, the solenoid valves (27) and (29) are switched respectively. The flow of liquid then flows from the cooling mechanism (30) to the heating mechanism (28).
). Then, the heating mechanism (28) heats the liquid that has become too cold. This causes the overly cooled liquid to return to the set temperature. Conversely, if the temperature of the liquid becomes too warm than the set temperature, the switching between heating and cooling described above is reversed.

In other words, when the temperature of the liquid exceeds the set temperature, the cooling mechanism (30
) and the heating mechanism (28), the liquid flowing through the channel (17) can always be maintained at a set temperature.

When the temperature of the lower electrode (15) is controlled in this way,
Stable etching processing can be performed.

In addition, the exhaust gas and semiconductor wafer (1'1) after etching
The exhaust inside the reaction vessel ω during Va delivery is carried out by the exhaust ring (22).
The reactor is appropriately exhausted by an exhaust device (IiM not shown) provided inside and outside the reaction vessel through an exhaust hole (21) and an exhaust pipe (23) provided in the reaction vessel.

In the above embodiment, an example was explained in which a circulation flow path equipped with a cooling mechanism and a heating mechanism at predetermined positions was provided on the lower surface of the lower electrode, but the present invention is not limited to this. It may be provided at a reliable location such as the side wall of the reaction vessel.

Furthermore, in the above embodiment, the processing apparatus was explained as being applied to an etching apparatus that uses plasma, but the present invention is not limited to this, and the same effect can be obtained even if it is applied to a CVD apparatus, an ion implantation apparatus, a sputtering apparatus, etc. Obtainable.

Further, in the above embodiment, an example in which the temperature is set during processing of the object to be processed has been described, but the present invention is not limited to this, and may be applied before, after, or during the processing.

Furthermore, the temperature regulating body to be circulated in the flow path does not have to be a liquid, and may be any gas, for example.

Furthermore, in the above embodiment, an example was explained in which the heating mechanism and the cooling mechanism were installed in parallel with the piping and operated independently, but the invention is not limited to this. For example, they may be operated at the same time, or they may be operated in series. A similar effect can be obtained even if it is provided in Furthermore, it goes without saying that any structure of the heating mechanism and cooling mechanism can be used.

Further, the flow switch and flow meter provided in the coolant flow conduit may be of any type, as long as they can monitor failure of one of them.

As described above, according to this embodiment, in a processing apparatus that processes an object to be processed at a predetermined temperature, a heating means and a cooling means are installed at a predetermined position in a medium circulation channel for setting the temperature. By providing each means, it is possible to correspond to the processing conditions of each type of product, resulting in high versatility.

Furthermore, by providing a heating mechanism and a cooling mechanism in the medium circulation flow path for setting the temperature.

If the cooling mechanism cools the temperature too much below the set temperature, the heating mechanism can warm up the too cold temperature controller and adjust it to the set temperature.
The cooling mechanism cools down the medium circulation channel that has been heated too much by the heating mechanism, allowing adjustment to the desired set temperature.

This makes it possible to maintain a predetermined set temperature and improves the accuracy of the process.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of an etching apparatus for explaining one embodiment of the apparatus of the present invention, Fig. 2 is an explanatory view of the temperature control mechanism of the apparatus shown in Fig. 1, and Fig. 3 is a cross-sectional view of the etching apparatus used in the temperature control mechanism of Fig. 2. FIG. 14... Semiconductor wafer 17... Channel 18...
・Piping 28...Heating mechanism 34...Flow meter 19...Temperature control mechanism 30...Cooling mechanism

Claims (1)

[Claims] 1. A processing apparatus for processing an object to be processed at a predetermined temperature, characterized in that a heating means and a cooling means are respectively provided at predetermined positions in a medium circulation flow path for setting the temperature.