JP3402129B2 - Substrate dry etching equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate dry etching apparatus for etching a substrate with plasma.

[0002]

2. Description of the Related Art Dry etching is used as a method for finely processing a substrate made of glass or the like. Dry etching involves placing a substrate on an electrode in a reduced pressure atmosphere, applying a high frequency voltage to the electrode to generate plasma,
Ions and electrons generated as a result are made to collide with the substrate for etching.

[0003]

By the way, in order to obtain a uniform etching effect on each part of the substrate by dry etching, it is desirable to make the periphery of the substrate placed on the electrode as uniform as possible in potential. Therefore, the impedance in the range where discharge is generated is made uniform by laying a spacer of a conductor along the outer periphery of the substrate.

However, in a dry etching apparatus for a substrate made of an insulating material such as glass, the following structural and functional requirements are required to make the impedance around the substrate placed on the electrode uniform. Therefore, it is difficult to evenly dispose the conductor spacers. First, since a substrate elevating member for loading and unloading a substrate on and from the electrode is arranged around the electrode, it is not possible to lay a conductor spacer in the range in which the substrate elevating member moves up and down. In addition, a recess is provided on the upper surface of the electrode on which the electrode is placed to form a gap between the substrate and the electrode, and the cooling gas is supplied to this gap for cooling the substrate during dry etching. It is necessary to press and fix the substrate to the electrode so that it is not blocked. For this reason, a substrate pressing member is arranged above the electrodes.

As described above, the structure around the substrate on the electrode is complicated, and the periphery of the substrate on the electrode is completely covered with a conductor to realize a uniform potential state during dry etching. However, there is a problem in that it is difficult to perform uniform etching.

Therefore, an object of the present invention is to provide a substrate dry etching apparatus which can perform uniform etching.

[0007]

A dry etching apparatus of the present invention includes a vacuum chamber, an electrode mounted on the vacuum chamber for mounting an insulating substrate on an upper surface thereof, and a power supply section for applying a high frequency voltage to the electrode. A recess formed on the upper surface of the electrode, a gas supply path communicating with the recess, a cooling gas supply section for supplying a cooling gas to the recess via the gas supply path, and a gas supply path mounted on the electrode. A spacer made of a conductor disposed on the electrode along the outer periphery of the substrate,
A substrate elevating member which receives an edge portion of the lower surface of the substrate and elevates and lowers the substrate on the electrode, and a pressing member which is made of a conductor and presses the substrate against the electrode from above and covers the upper surface of the substrate elevating member. And the spacer and the pressing portion.
A conductive material around the substrate mounted on the electrode
I covered it with .

[0008]

According to the present invention having the above-described structure, a spacer made of a conductor is laid along the outer periphery of the substrate on the electrode, and a spacer having a shape of the conductor covering the upper surface of the substrate elevating member is formed. By providing the pressing member, the periphery of the substrate is completely covered with the conductor, so that the potential becomes uniform and uniform etching can be performed.

Next, embodiments of the present invention will be described with reference to the drawings. 1 is a front sectional view of a substrate dry etching apparatus according to an embodiment of the present invention, FIG. 2 is a partial perspective view of the substrate dry etching apparatus, and FIG. 3 is a partial plan view of the substrate dry etching apparatus. 4 is a front sectional view of the dry etching apparatus for the substrate, FIGS. 5A and 5B are graphs showing the etching rate of the dry etching apparatus for the substrate,
FIG. 6 is a front sectional view of a dry etching apparatus for the same substrate.

First, the overall structure of a substrate dry etching apparatus will be described with reference to FIGS. In FIG. 1, 1
Is a vacuum chamber, which is a cylindrical vacuum-tight container. An electrode 2 is attached to the bottom surface of the vacuum chamber 1 via an insulator 3. A circular recess 2a having a depth of about several tens of microns is formed on the upper surface of the electrode 2. A substrate 10 is placed on the upper surface of the electrode 2 with its edge supported by the electrode 2, and the central portion of the substrate 10 is separated from the electrode 2 by a recess 2a with a slight gap.

The recess 2a communicates with a first conduit 4a provided in the electrode 2, and the first conduit 4a is connected to the second conduit 4a.
It communicates with b. The second conduit 4b is provided in the conduit member 5 that is inserted and inserted through the insulator 3. The second pipeline 4b is the third pipeline 4 provided outside the vacuum chamber 1.
It is connected to the cooling gas supply unit 8 via c. By supplying a cooling gas such as helium from the cooling gas supply unit 8 into the recess 2a through the third pipe line 4c, the second pipe line 4b and the first pipe line 4a, the cooling gas is dry-etched. The substrate 10 whose temperature has risen by is cooled, and then is diffused into the vacuum chamber 11 through the gap between the substrate 10 and the electrode 2.

A space 2b is provided inside the electrode 2 and is connected to the cooling unit 7 via pipe lines 6a and 6b. The cooling water sent from the cooling unit 7 circulates in the pipes 6a, 6b and the space 2b to cool the electrode 2 whose temperature has risen due to plasma discharge. Grooves 2c are provided at three locations on the upper surface of the electrode 2 (see FIG. 2), and elevating claws 11 made of an insulating material such as a resin material as a substrate elevating member are fitted in the grooves 2c. The lifting claw 11 is connected to the rod 12, and the rod 12 is used to lift the substrate 1.
By moving up and down by 3, the substrate 10 placed on the electrode 2 is moved up and down in the vacuum chamber 11.

In FIG. 2, an annular spacer 20 made of carbon, which is a conductor, is arranged on the electrode 2. The spacer 20 is divided into three, and is arranged along the outer periphery of the substrate 10 except for the groove portion 2c. Therefore, the spacer 20 does not interfere with the vertical movement of the lifting claw 11.
Reference numeral 21 is a pressing member for an annular substrate made of carbon, which is a conductor, and as shown in FIG. 2, projections 21a are provided at three locations corresponding to the position of the lifting claw 11 toward the inside. The pressing member 21 presses the substrate 10 onto the upper surface of the electrode 2 from above by the lower surface of the protrusion 21a. Presser member 2
1 is connected to rods 23 of three cylinders 24 via three blocks 22. Therefore, when the rod 23 of the cylinder 24 is projected and retracted, the pressing member 21 moves up and down in the vacuum chamber 1, and the substrate 10 is pressed and fixed onto the upper surface of the electrode 2 in the lowered state. That is, the pressing member 2
1. The cylinder 24 serves as a fixing means for the substrate 10.

In FIG. 1, the electrode 2 is a high frequency power source 16
The high frequency power supply 16 is electrically grounded to a grounding portion 17 common to the vacuum chamber 1.
An upper electrode 25 is provided in the upper part of the vacuum chamber 1, and a high frequency voltage is applied between the upper electrode 25 and the electrode 2. The vacuum chamber 1 is provided with pipes 14 and 26, which are connected to a vacuum exhaust unit 15 and a plasma gas supply unit 27, respectively. The vacuum exhaust unit 15 vacuum-sucks the inside of the vacuum chamber 1 to reduce the pressure. Plasma gas supply unit 2
Reference numeral 7 supplies a gas for plasma generation into the vacuum chamber 1.

In FIG. 3, the substrate 10 is placed on the electrode 2,
1 is a plan view of the substrate 10 being pressed by a pressing member 21 from above. As shown in FIG. 3, carbon spacers 20 are laid around the substrate 10. Further, the outside is a carbon pressing member 2
1 and the spacer 2 by the lifting claw 11.
In the range where 0 is divided, the protrusion 21a of the pressing member 21 covers the upper side. That is, the periphery of the substrate 10 is completely covered with carbon, which is a conductor, and a potential is uniform in generating a discharge between the electrode 2 and the upper electrode 25, that is, the impedance of each part is uniform. Has been realized.

This dry etching apparatus has the above-mentioned structure, and its operation will be described with reference to the drawings.

In FIG. 4, reference numeral 50 denotes a transfer arm,
The substrate 10 is loaded into the vacuum chamber 1 through the opening 1a of the vacuum chamber 1 (see arrow a), and then descends (see arrow b) onto the elevating claw 11 in the ascending state. After mounting (indicated by a broken line), the robot moves out of the vacuum chamber 1 (see arrow c). After this, the lifting claw 11
Lowers to place the substrate 10 on the electrode 2, then the substrate pressing member 21 lowers to press the substrate 10 onto the electrode 2,
The state shown in FIG. 1 is obtained.

Next, the vacuum evacuation unit 15 is driven to evacuate the inside of the vacuum chamber 1 and then the plasma gas supply unit 27.
The plasma generating gas is supplied to the vacuum chamber 1 further. Next, when the high frequency power supply 16 is driven to apply a high frequency voltage to the electrode 2, plasma is generated between the electrode 2 and the upper electrode 25, and the ions and electrons generated as a result are generated in the substrate 10.
The dry etching is performed by colliding with the surface of. At this time, the cooling gas supply unit 8 is installed in the recess 2a of the electrode 2.
More cooling gas is supplied. As a result, the substrate 10 heated by the heat generated by the dry etching is cooled.

Next, the distribution of the etching rate on the substrate, which is an index showing the dry etching effect of plasma, will be described with reference to FIGS. 5 (a) and 5 (b). When a high frequency voltage is applied between the electrode 2 and the upper electrode 25 and a discharge is generated between these electrodes, a high frequency current flows between the electrode 2 and the upper electrode 25 with a space. in this case,
If the impedance indicating the difficulty of the flow of the high frequency current is not uniform within the range in which the discharge is generated, the high frequency current flows unevenly in the part where the high frequency current easily flows, and as a result, the etching rate distribution showing the effect of etching is also uneven. It becomes uniform. 5A and 5B show distributions of etching rates on the AA cross section (see FIG. 2) when the pressing member 21 that presses the substrate 10 is an insulator and a conductor, respectively. It is shown in the graph.

In FIG. 5A, since the pressing member 21 is an insulator, the high-frequency current does not flow in this portion, but as shown by an arrow h, the high-frequency current flows unevenly in the range of the substrate 10, so that the etching rate is shown. The graph i shows a tendency that it is high in the central portion of the substrate 10 and largely decreases in the peripheral portion. On the other hand, when the pressing member 21 is a conductor such as carbon, the high-frequency current also flows in the range of the pressing member 21 (see arrow j) as shown in FIG. 5B, and a graph showing the etching rate. k only slightly decreases at the boundary between the substrate 10 and the pressing member 11, and maintains a substantially uniform level.

Although the etching effect does not reach the portion of the edge of the substrate 10 covered by the pressing member 21,
Since this part is cut off in a later process and is not used as a product, there is no problem in quality.

As described above, by completely covering the periphery of the substrate 10 with the conductor, the impedance distribution around the substrate 10 can be made more uniform, and a uniform etching effect can be obtained on the entire surface of the substrate 10. Obtainable. Further, since the lifting claw 11 is electrically grounded and is close to the electrode 2, it is made of an insulating material such as resin so as not to come into contact with the electrode 2 and electrically short-circuit. Therefore, the thermal conductivity is low, and the temperature tends to rise when heated by dry etching. Therefore, the pressing member 11
By covering the upper surface of the lifting / lowering claw 11 with the above, it is possible to suppress the temperature rise during the dry etching and prevent a defect such as deformation due to the temperature rise.

Further, by using carbon, which is a conductor, as the material of the spacer 20 and the pressing member 21,
The spacer 20 and the pressing member 2 are dry-etched.
Since the carbon particles removed from 12 and scattered are vaporized and diffused, they are not redeposited as foreign matter on the substrate 10 and contaminate the substrate 10.

Next, when the dry etching is completed, as shown in FIG. 6, the substrate 10 is unloaded in the reverse order of the loading operation. First, the elevating claw 11 is raised to raise the substrate 10 (shown by a broken line) (see arrow d), and then the transfer arm 5
0 enters below the substrate 10 (see arrow e). Next, the transfer arm 50 rises (see the arrow f), places the substrate 10 on the transfer arm 50, and then retracts (see the arrow g) to carry the substrate 10 out of the vacuum chamber 1 for one cycle of dry etching. finish.

[0025]

According to the present invention, a spacer made of a conductor is laid along the outer periphery of a substrate on an electrode, and a pressing member having a shape covering the upper surface of the substrate elevating member made of a conductor is provided. Since the periphery of the substrate is completely covered with the conductor, the potential becomes uniform and uniform etching can be performed. By covering the upper surface of the substrate elevating / lowering member with the pressing member, it is possible to suppress a temperature rise during the dry etching of the substrate elevating / lowering member and prevent a defect such as deformation due to a temperature increase. Furthermore, if carbon is used as the material of the conductor of the spacer or the pressing member, the carbon particles that are removed from the spacer or the pressing member by dry etching and are scattered will be vaporized and diffused, so that the carbon particles will be reattached to the substrate as foreign matter and contaminate the substrate. There is no.

[Brief description of drawings]

FIG. 1 is a front sectional view of a substrate dry etching apparatus according to an embodiment of the present invention.

FIG. 2 is a partial perspective view of a substrate dry etching apparatus according to an embodiment of the present invention.

FIG. 3 is a partial plan view of a substrate dry etching apparatus according to an embodiment of the present invention.

FIG. 4 is a front sectional view of a substrate dry etching apparatus according to an embodiment of the present invention.

5A is a graph showing an etching rate of a substrate dry etching apparatus according to an embodiment of the present invention. FIG. 5B is a graph showing an etching rate of a substrate dry etching apparatus according to an embodiment of the present invention.

FIG. 6 is a front sectional view of a substrate dry etching apparatus according to an embodiment of the present invention.

[Explanation of symbols]

1 vacuum chamber 2 electrodes 2a recess 3 insulator 4a First pipeline 4b second conduit 4c Third pipeline 5 Pipe member 7 Cooling unit 8 Cooling gas supply unit 10 substrates 11 Lifting claw 20 spacers 21 Presser member 21a protrusion 24 cylinders 25 upper electrode

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01L 21/3065 C23F 4/00 H01L 21/68

Claims (2)

(57) [Claims] 1. A vacuum chamber, an electrode mounted on the vacuum chamber for mounting an insulating substrate on an upper surface thereof, a power source section for applying a high frequency voltage to the electrode, and an electrode formed on the upper surface of the electrode. A concave portion whose upper side is closed by the placed substrate, a gas supply passage communicating with the concave portion, a cooling gas supply portion for supplying a cooling gas to the concave portion via the gas supply passage, and a gas supply passage mounted on the electrode. before along the outer periphery of the location by the substrate
A spacer made of a conductor disposed on the electrode, a substrate elevating member for lowering the edge of the lower surface of the substrate to raise and lower the substrate on the electrode, and a substrate made of a conductor from above the electrode And a pressing member that presses against the upper surface of the substrate elevating member and covers the spacer and the pressing member.
Cover the substrate mounted on the electrode with a conductor.
Dry etching apparatus of the substrate, characterized in that the Migihitsuji. 2. The spacer and the pressing member are made of carbon.
2. The substrate drier according to claim 1, wherein
Touching device.