JP3967520B2 - Dry etching equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a dry etching apparatus, and more particularly to a dry etching apparatus suitable for processing a substrate to be processed whose both surfaces are etched like a printed board.
[0002]
[Prior art]
In the conventional chemical dry etching method, when only one surface of the substrate to be processed is processed, radicals are supplied in a direction perpendicular to the etching surface. On the other hand, in the case of a substrate to be processed that needs to be etched on both sides like a printed circuit board, radicals are supplied from the side to the etching surface of the substrate to be processed.
[0003]
When supplying radicals from the side to the etching surface of the substrate to be processed, a gas inlet side through which a process gas containing radicals is introduced into the processing chamber, and a gas for exhausting the gas in the processing chamber to the outside of the processing chamber The supply amount of radicals supplied to the etching surface is different on the exhaust port side. For this reason, the distribution of the etching rate in the etching surface is biased, and the in-plane uniformity of the etching process is deteriorated.
[0004]
In order to cope with this problem, a method has been proposed in which the workpiece to be processed is rotated to make the etching rate uniform in the etching surface. This method is particularly effective for a disk-shaped substrate to be processed such as a silicon wafer.
[0005]
[Problems to be solved by the invention]
However, in the case of a rectangular target substrate such as a rectangle, even if etching processing is performed while rotating the target substrate, the etching rate distribution in the etching surface is not a concentric circle but a complicated distribution due to the shape. turn into. For this reason, simply rotating the substrate to be processed at an equal angular velocity results in etching with poor in-plane uniformity, and cannot improve the in-plane uniformity.
[0006]
The reason why the etching rate distribution is complicated in the non-circular substrate to be processed is that, when the angular velocity is constant, the peripheral velocity increases as the distance from the center of rotation increases, and the supply of radicals increases as the peripheral velocity increases. This is considered to be because the etching time is lowered because the time taken is reduced.
[0007]
Since the distribution of the etching rate in the etching surface when the substrate to be processed is rotated at an equiangular speed changes depending on the shape of the substrate to be processed, the etching surface is uniform even for various shapes of the substrate to be processed. There is a demand for a dry etching apparatus capable of ensuring the performance.
[0008]
The present invention has been made in consideration of the above-described circumstances, and an object of the present invention is to provide a dry etching apparatus capable of etching various shapes of substrates to be processed with good in-plane uniformity. And
[0009]
[Means for Solving the Problems]
In order to solve the above problems, a dry etching apparatus according to the present invention includes a vacuum vessel in which a processing chamber for etching a non-circular substrate to be processed is formed, and a process gas introduced into the processing chamber. An exhaust port for exhausting the interior of the processing chamber, and holding the substrate to be processed inside the processing chamber. A rotation holding means that rotates together, a plasma generation means that generates a plasma by irradiating a process gas with microwaves, and a process gas excited by the plasma generated by the plasma generation means, including the gas inlet. The etching surface of the substrate to be processed is discharged from the side of the substrate to be processed held by the rotation holding means to the substrate to be processed through the gas introduction port. In order to make the supply amount of the process gas to the substrate to be processed uniform over the entire etching surface, the angular velocity of the rotation of the substrate to be processed by the rotation holding unit is set to one rotation. And a rotation control means for changing.
[0010]
Preferably, the rotation control means rotates the substrate to be processed based on a distance from a rotation center of the substrate to be processed to a peripheral edge of the substrate to be processed when measured in the direction of the gas inlet. Control the angular velocity of
[0011]
Preferably, the rotation control means adjusts the angular velocity of rotation of the substrate to be processed so that the peripheral velocity of the periphery of the substrate to be processed measured at a position facing the gas introduction port is constant during one rotation. Control.
[0012]
Preferably, the rotation control means is configured so that the etching in-plane distribution is uniform in consideration of an etching in-plane distribution of an etching rate when the substrate to be processed is etched while rotating at a constant angular velocity. The angular velocity of rotation of the substrate to be processed is controlled.
[0013]
Preferably, the rotation control means has a function of stopping the rotation operation of the substrate to be processed during the processing.
[0014]
Preferably, the rotation control means stops the rotation operation of the substrate to be processed at least once per rotation during the process.
[0015]
Preferably, when the substrate to be processed has a polygonal shape, the number of rotations of the rotation of the substrate to be processed per rotation is equal to or more than the number of corners of the substrate to be processed.
[0016]
Preferably, when the corner of the substrate to be processed comes to a position facing the gas introduction port and when the center of the side of the substrate to be treated comes to a position facing the gas introduction port, The rotation operation of the processing substrate is stopped.
[0017]
Preferably, the rotation control unit is configured to measure the stop time when the rotation operation of the substrate to be processed is stopped from the rotation center of the substrate to be processed toward the gas inlet. This is determined based on the distance to the periphery of the substrate to be processed.
[0018]
Preferably, the rotation control means rotates the substrate to be processed at an equiangular speed except when stopped.
[0019]
Preferably, the rotation control means is configured so that the peripheral speed of the peripheral edge of the substrate to be measured, which is measured at a position facing the gas introduction port, is constant during one rotation except during a stop. The angular velocity of rotation of the processing substrate is controlled.
[0020]
Preferably, the rotation holding means includes a substrate receiver that holds the substrate to be processed, a rotation drive source that generates a rotational force at a constant angular velocity for rotating the substrate receiver, and a rotation from the rotation drive source. A driving force transmission mechanism that transmits a force to the substrate receiver by a mechanical transmission method, and the rotation control means changes an angular speed of the substrate to be processed by changing a gear ratio in the driving force transmission mechanism. To control.
[0021]
Preferably, the rotation holding unit includes a substrate receiver that holds the substrate to be processed, and a rotation drive source that generates a rotational force for rotating the substrate receiver, and the rotation control unit includes: The angular velocity of rotation of the substrate to be processed is controlled by changing the angular velocity of rotation of the rotation drive source.
[0022]
Preferably, both the front surface and the back surface of the substrate to be processed are etched, and the rotation holding means supports the edge of the substrate to be processed and supports the surface of the substrate to be processed. The entire processing area on the back surface is exposed in the processing chamber.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a dry etching apparatus according to an embodiment of the present invention will be described with reference to the drawings.
[0024]
FIG. 1 is a longitudinal sectional view showing a schematic configuration of a dry etching apparatus according to the present embodiment. This dry etching apparatus includes a vacuum vessel 2 in which a processing chamber 1 is formed, and the vacuum vessel 2 is a vessel body. 3 and a lid 4.
[0025]
The dry etching apparatus further includes a rotation holding means 5 having a function of holding the printed board S being processed and a function of rotating the held printed board S. The rotation holding means 5 supports the printed board S. It has a frame-shaped substrate receiver 6 and a rotating shaft 7 connected to the substrate receiver 6.
[0026]
The frame-shaped substrate receiver 6 supports only the edge portion of the printed circuit board S so that the entire processing area of the front surface and the back surface of the printed circuit board S can be exposed in the processing chamber 1.
[0027]
Plasma generating means 8 is provided on the side of the vacuum vessel 2, and plasma is generated by irradiating the process gas with microwaves. A gas supply unit 9 is connected to the plasma generation unit 8, and the process gas excited by the plasma generated by the plasma generation unit 8 is received by the substrate of the rotation holding unit 5 through the gas supply unit 9. 6 is discharged from the side of the printed circuit board S held at 6 toward the printed circuit board S, and a process gas containing radicals is simultaneously supplied to both the front surface and the back surface of the printed circuit board S.
[0028]
The gas supply means 9 includes a gas introduction port 10 disposed on the side of the printed circuit board S held by the substrate holder 6 of the rotation holding means 5, and a communication pipe connecting the gas introduction port 10 and the plasma generation means 8. 11. The gas inlet 10 includes a front-side gas nozzle 10 a that supplies process gas to the front side of the printed circuit board S and a back-side gas nozzle 10 b that supplies process gas to the back side of the printed circuit board S. The process gas is supplied from the common plasma generating means 8 to the front side gas nozzle 10a and the back side gas nozzle 10b through the connecting pipe 11.
[0029]
Further, an exhaust port 13 for exhausting the inside of the processing chamber 1 is provided on the wall of the vacuum vessel 2 at a position facing the gas introduction port 10 with the printed board S interposed therebetween. Since the gas introduction port 10 and the exhaust port 13 are arranged to face each other with the printed board S interposed therebetween, the process gas introduced from the gas introduction port 10 into the processing chamber 1 is transferred to the front and back surfaces of the printed board S. It is easy to spread evenly from one end to the other along.
[0030]
Furthermore, the dry etching apparatus according to the present embodiment is provided with a rotation control means 14, which is a rotation holding means for equalizing the amount of process gas supplied to the printed circuit board S over the entire etching surface. 5 can be changed during one rotation. Further, the rotation control means 14 has a function of stopping the rotation operation of the printed circuit board S during the process.
[0031]
A rotational force for rotating the rotating shaft 7 and the substrate receiver 6 is generated by a rotational driving source 15, and this rotational force is transmitted to the rotating shaft 7 and the substrate receiver 6 by a mechanical transmission type driving force transmission mechanism 16. . When controlling the angular speed of rotation of the printed circuit board S, the rotation control means 14 changes the gear ratio in the driving force transmission mechanism 16 or changes the angular speed itself of rotation of the rotational drive source 15 to change the printed circuit board S. It is also possible to control the angular velocity of the rotation.
[0032]
As an example of the control method by the rotation control means 14, as shown in FIG. 2, based on the distance from the rotation center of the printed circuit board S to the periphery of the printed circuit board S when measured in the direction of the gas inlet 10. The angular speed of rotation of the printed circuit board S is controlled. Specifically, control is performed such that the angular velocity of rotation is slower as the distance from the center of rotation to the periphery is longer. Preferably, the angular speed of rotation of the printed circuit board S is controlled so that the peripheral speed of the peripheral edge of the printed circuit board S measured at a position facing the gas inlet 10 is constant over one rotation.
[0033]
Further, as another example of the control method by the rotation control means 14, the etching in-plane distribution of the etching rate when the printed board S is etched while rotating at a constant angular velocity is measured in advance, and this etching rate is measured. In consideration of the etching in-plane distribution, the angular velocity of rotation of the printed circuit board S is controlled so that the etching in-plane distribution is uniform.
[0034]
Further, as another example of the control method by the rotation control means 14, as shown in FIG. 3, the rotation operation of the printed circuit board S is stopped at least once per rotation during the process.
[0035]
Here, when the printed circuit board S has a polygonal shape such as a rectangle, it is preferable that the number of rotations of the rotation of the printed circuit board S per rotation is equal to or greater than the number of corners of the printed circuit board S.
[0036]
More specifically, as shown in FIG. 3, when the corner portion of the printed circuit board S comes to a position facing the gas introduction port 10 and the position where the center of the side of the printed circuit board S faces the gas introduction port 10. Rotation of the printed circuit board S is stopped when
[0037]
Further, the stop time when the rotation operation of the printed circuit board S is stopped is determined based on the distance from the rotation center of the printed circuit board S to the periphery of the printed circuit board S when measured in the direction of the gas inlet 10. can do. Specifically, control is performed such that the longer the distance from the rotation center to the peripheral edge, the longer the stop time.
[0038]
Further, in the case of the above-described control method in which the rotation operation of the printed circuit board S is stopped during processing, the printed circuit board S is rotated at a constant angular velocity or at a position facing the gas inlet 10 except during the stop time. The angular velocity of the rotation of the printed circuit board S may be controlled so that the measured peripheral speed of the peripheral edge of the printed circuit board S is constant over one rotation.
[0039]
As described above, according to the dry etching apparatus of the present embodiment, the rotation control means 14 rotates the printed board S by the rotation holding means 5 in order to make the process gas supply to the printed board S uniform over the entire etching surface. Since the angular velocity is changed during one rotation, it is possible to improve the in-plane uniformity of the processing when the non-circular printed board S is etched.
[0040]
In addition, the dry etching apparatus according to the present embodiment can easily cope with the printed circuit boards S having various shapes, and the versatility of the apparatus is extremely high.
[0041]
Furthermore, according to the dry etching apparatus according to the present embodiment, the excited process gas is supplied from the side of the printed circuit board S so that both surfaces of the printed circuit board S are simultaneously etched. The processing time of the substrate S can be shortened.
[0042]
【The invention's effect】
As described above, according to the dry etching apparatus of the present invention, in order to make the supply of the process gas to the substrate to be processed uniform over the entire etching surface, the rotation control means sets the rotation angular velocity of the substrate to be processed by the rotation holding means. Since it is changed during one rotation, the in-plane uniformity of processing when a non-circular substrate to be processed is etched can be improved. Further, it is possible to easily cope with substrates to be processed in various shapes, and the versatility of the apparatus is extremely high.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a schematic configuration of a dry etching apparatus according to an embodiment of the present invention.
FIG. 2 is an explanatory diagram for explaining an example of a control method of a dry etching apparatus according to an embodiment of the present invention.
FIG. 3 is an explanatory diagram for explaining another example of a control method of a dry etching apparatus according to an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Processing chamber 2 Vacuum container 3 Container body 4 Cover part 5 Rotation holding means 6 Substrate receptacle 7 Rotating shaft 8 Plasma generation means 9 Gas supply means 10 Gas inlet 10a Front side gas nozzle 10b Back side gas nozzle 11 Connecting pipe 13 Exhaust port 14 Rotation Control means 15 Rotation drive source 16 Drive force transmission mechanism S Printed circuit board (substrate to be processed)

Claims (14)

A vacuum chamber in which a processing chamber for etching a non-circular target substrate is formed;
An exhaust port for exhausting the inside of the processing chamber, disposed at a position facing the gas inlet for introducing a process gas into the processing chamber with the substrate to be processed interposed therebetween;
Rotation holding means for holding and rotating the substrate to be processed inside the processing chamber;
Plasma generating means for generating plasma by irradiating the process gas with microwaves;
A process gas including the gas introduction port and excited by the plasma generated by the plasma generation unit is passed through the gas introduction port from the side of the substrate to be processed held by the rotation holding unit. Gas supply means for discharging toward the processing substrate and supplying a process gas to the etching surface of the substrate to be processed;
Rotation control means for changing the angular velocity of rotation of the substrate to be processed by the rotation holding means during one rotation in order to make the supply amount of the process gas to the substrate to be processed uniform over the entire etching surface. A dry etching apparatus characterized by that.   The rotation control unit controls an angular velocity of rotation of the substrate to be processed based on a distance from a rotation center of the substrate to be processed to a periphery of the substrate to be processed when measured in the direction of the gas introduction port. The dry etching apparatus according to claim 1.   The rotation control unit controls an angular velocity of rotation of the substrate to be processed so that a peripheral velocity of the periphery of the substrate to be processed measured at a position facing the gas introduction port is constant during one rotation. The dry etching apparatus according to claim 2.   The rotation control means takes into account the etching in-plane distribution of the etching rate when etching is performed while rotating the substrate to be processed at an equiangular speed, so that the in-etch distribution is uniform. The dry etching apparatus according to claim 1, wherein an angular velocity of rotation of the substrate is controlled.   The dry etching apparatus according to claim 1, wherein the rotation control unit has a function of stopping the rotation operation of the substrate to be processed in the middle of processing.   6. The dry etching apparatus according to claim 5, wherein the rotation control means stops the rotation operation of the substrate to be processed at least once per rotation during the process.   The said process substrate has polygonal shape, The frequency | count of the stop of the rotation operation | movement of the said process substrate per rotation is the same as or more than the number of corners of the said process substrate, The said characterized by the above-mentioned. Dry etching equipment.   Rotating operation of the substrate to be processed when the corner of the substrate to be processed comes to a position facing the gas inlet and when the center of the side of the substrate to be processed comes to a position facing the gas inlet The dry etching apparatus according to claim 7, wherein the dry etching apparatus is stopped.   The rotation control means is a peripheral edge of the substrate to be processed when a stop time when the rotation operation of the substrate to be processed is stopped is measured from the rotation center of the substrate to be processed toward the gas inlet. The dry etching apparatus according to claim 5, wherein the dry etching apparatus determines the distance based on the distance up to.   The dry etching apparatus according to any one of claims 5 to 9, wherein the rotation control unit rotates the substrate to be processed at an equiangular speed except when stopped.   The rotation control means is configured to rotate the substrate to be processed so that a peripheral speed of the periphery of the substrate to be measured measured at a position facing the gas introduction port is constant during one rotation except during a stop. The dry etching apparatus according to claim 5, wherein the angular velocity is controlled. The rotation holding means mechanically transmits the rotation force from the rotation drive source, a substrate receiver that holds the substrate to be processed, a rotation drive source that generates a rotation force at a constant angular velocity for rotating the substrate receiver, A driving force transmission mechanism for transmitting to the substrate receiver by a method,
The dry etching according to any one of claims 1 to 11, wherein the rotation control unit controls an angular velocity of rotation of the substrate to be processed by changing a transmission gear ratio in the driving force transmission mechanism. apparatus. The rotation holding unit includes a substrate receiver that holds the substrate to be processed, and a rotation drive source that generates a rotational force for rotating the substrate receiver.
12. The dry etching according to claim 1, wherein the rotation control unit controls an angular velocity of rotation of the substrate to be processed by changing an angular velocity of rotation of the rotation drive source. apparatus. The substrate to be treated is one in which both the front and back surfaces are etched.
2. The rotation holding unit is configured to expose an entire processing region of each of a front surface and a back surface of the substrate to be processed in the processing chamber by supporting an edge portion of the substrate to be processed. The dry etching apparatus as described in any one of thru | or 13.

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