JP2005093705A - Device and method for plasma generation - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasma-generating device and a plasma generating method in which if the etching selectivity with respect to mask is small, the thickness of the mask can be made small, and also the in-plane uniformity of an etching speed is proper. <P>SOLUTION: In an etching device (plasma-generating device) 10, in which a plasma is formed by generating an induced electric field in a chamber 20, the etching device is formed with a member 30 which is disposed in the chamber 20 and is disposed so as to face a semiconductor wafer W having a plurality of processing regions, and a plurality of electric circuit element (plasma-generating electrode) 40 corresponding to the plurality of processing regions, respectively, and formed on the wafer W side of the member 30. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a plasma generation apparatus and a plasma processing method, and more particularly to an apparatus incorporated in an etching apparatus for manufacturing or painting a thin film element on a semiconductor device or a liquid crystal panel.

  Conventionally, dry etching apparatuses (plasma generating apparatuses) for manufacturing semiconductor devices are known. The dry etching apparatus includes a chamber in which a semiconductor wafer or the like to be processed is accommodated and plasma is generated. The chamber is provided with an exhaust device and a pressure adjusting device for adjusting the pressure in the chamber, and the pressure of the reaction gas introduced from the gas inlet is controlled.

  An opening is provided in the ceiling of the chamber, for example, a dielectric window such as quartz or alumina or a window made of semiconductor such as silicon is attached, and an antenna section is provided along the outer surface of the window. High frequency power is supplied to the antenna unit. A lower electrode to which high-frequency power is supplied is provided in the chamber, and a semiconductor wafer is placed via a holding mechanism.

In such a dry etching apparatus, plasma is generated in the chamber by introducing a reactive gas into the chamber and supplying high-frequency power to the antenna unit and the lower electrode, and particles in the plasma are transferred to the semiconductor through a mask. A desired pattern is transferred by colliding with the wafer (for example, see Patent Document 1).
JP 2002-217175 A

  The etching apparatus using the plasma generation apparatus described above has the following problems. That is, when a fine pattern is formed on a semiconductor wafer, it is necessary to perform etching using a thin mask. However, when etching is performed, the semiconductor wafer is also etched, and the mask is also etched to some extent by the etching, so that a certain thickness or more must be ensured. That is, when the difference in workability between the mask and the film to be etched is small, that is, when the etching selectivity of the film to be etched is insufficient, the mask needs to be thicker than a certain thickness.

  In addition, since it is difficult to generate plasma uniformly over the entire surface of the semiconductor wafer, insufficient in-plane uniformity of the etching rate becomes a problem.

  Accordingly, the present invention can reduce the mask thickness even if the etching selectivity to the mask is small, can achieve a fine pattern, and can provide a plasma generating apparatus and a plasma having excellent in-plane uniformity of the etching rate. It aims to provide a processing method.

  In order to solve the above problems and achieve the object, the plasma generating apparatus and the plasma processing method of the present invention are configured as follows.

(1) In a plasma generating apparatus for generating plasma by generating an induction electric field in a container, a member disposed in the container and disposed opposite to a target object having a plurality of processing regions, and the target of the member A plurality of plasma generating electrodes respectively corresponding to the plurality of processing regions are formed on the processing body side.

(2) In the plasma generating apparatus described in the above (1), the plasma generating electrode includes a recess formed in the member and having an opening on the object side, and a conductive provided on the bottom surface side of the recess. It is characterized by having a body.

(3) In the plasma generating apparatus described in (1) above, the member is formed over at least a region wider than the surface to be processed of the object to be processed.

(4) In the plasma generation apparatus described in (1), the member is formed to be movable relative to the object to be processed along the surface direction.

(5) In a plasma generation method for generating plasma by generating an induction electric field in a container, a positioning step of disposing the object to be processed disposed in the container and having a plurality of processing regions; And a plasma generation step of generating a plurality of plasmas by a plurality of plasma generation electrodes respectively formed on the processing body side and corresponding to the plurality of processing regions.

  According to the present invention, the mask thickness can be reduced even when the etching selectivity to the mask is small, the pattern can be miniaturized, and the in-plane uniformity of the etching rate can be kept good. It becomes.

  In an etching apparatus (plasma generating apparatus) 10 that generates plasma by generating an induced electric field in the chamber 20, a dielectric plate 31 that is disposed in the chamber 20 and is opposed to a semiconductor wafer W having a plurality of processing regions; A plurality of electric circuit elements (plasma generating electrodes) 40 are formed on the side of the semiconductor wafer W of the dielectric plate 31 and respectively correspond to a plurality of processing regions.

  FIG. 1 is a cross-sectional view schematically showing an etching apparatus (plasma generating apparatus) 10 according to a first embodiment of the present invention. The etching apparatus 10 includes a chamber 20 made of a metal vacuum vessel such as aluminum or stainless steel.

  The chamber 20 is formed with a gas inlet 21 and a carry-in / out port 22 for a semiconductor wafer W which is an object to be processed. Further, an exhaust mechanism 24 is connected via the pressure adjusting mechanism 23, and the pressure of the reaction gas introduced from the gas inlet 21 can be controlled in the range of 0.05 Pa to 500 Pa. In FIG. 1, reference numeral 25 denotes a pressure gauge.

  A plasma generator 30 is provided on the upper wall side of the chamber 20. The plasma generating unit 30 includes, for example, a dielectric plate 31 such as quartz or alumina, a plurality of concave portions 32 provided in a matrix on the lower surface side of the dielectric plate 31, and an induction electric field provided in each of the concave portions 32. And an electric circuit element (plasma generating electrode) 40 to be generated. The recess 32 is formed in a square shape having a side of 100 μm. The electric circuit element 40 is configured by connecting a conductor line 41 made of a conductor such as copper or aluminum and a capacitor 42. In order to avoid metal contamination of the semiconductor wafer W due to the etching of the conductor line 41, the surface of the recess 32 may be covered with an insulating film.

  One end of the conductor line 41 of each electric circuit element 40 is connected to a place having the same potential as the chamber 20, and the other end is connected to a power supply 52 via a switching circuit 50 and a matching circuit 51. The power supply 52 supplies a current having a frequency of several MHz to several hundred MHz, and is supplied to each electric circuit element 40 via the switching circuit 50. The switching circuit 50 is configured to be able to independently control ON / OFF of power supply to the electric circuit element 40.

  In the figure, reference numeral 60 denotes a lower electrode. The lower electrode 60 can hold the semiconductor wafer W via a holding mechanism 61. A power source 63 is connected to the lower electrode 60 via a matching circuit 62. The power source 63 controls the ion energy with which power of a frequency of several hundred kHz to several hundred MHz is incident on the semiconductor wafer W. The power source 63 is controlled independently of the power source 52 described above.

  In the etching apparatus 10 configured as described above, the etching target film formed on the semiconductor wafer W is etched as follows. That is, the semiconductor wafer W on which the mask M is laminated on the processing surface is loaded into the chamber 20 from the loading / unloading port 22 and placed on the holding member 61. At this time, the distance between the upper surface of the mask M and the lower surface of the plasma generation unit 30 is several mm. Next, the inside of the chamber 20 is decompressed by the exhaust mechanism 24, and then the reaction gas is introduced from the gas inlet 21. Note that the pressure in the chamber 20 is kept constant by the pressure adjusting mechanism 23.

  Next, the power source 52 and the power source 63 are controlled to supply power to the plasma generation unit 30 and the lower electrode 60, respectively. The electric circuit element 40 to be energized is selected by the switching circuit 50, and the plasma P is generated only at the lower part of the energized electric circuit element 40. Thereby, the etching target film corresponding to the opening of the mask M is etched and removed. Therefore, it is possible to perform etching only for necessary portions.

  Further, even when the whole is etched at the same time, it becomes possible to arbitrarily control the intensity of the plasma by turning on / off the current to the electric circuit element 40, adjusting the current amount, etc. It is possible to adjust the etching rate uniformity.

  In addition to the configuration in which the plasma generating unit 30 has the same shape and the same area as the semiconductor wafer W, the electric circuit elements 40 may be arranged in a line. In such a plasma generation unit 30, it is possible to perform etching sequentially by moving the upper surface side of the semiconductor wafer W in parallel with the surface of the semiconductor wafer W, and it is possible to cope with semiconductor wafers W of various sizes and shapes. There is a merit that you can.

  As described above, according to the etching apparatus 10 according to the present embodiment, the plasma can be generated only in the region of the semiconductor wafer W where the etching process is performed. Therefore, the amount by which the mask M itself is etched during the etching process. And the thickness of the mask M can be minimized. Further, the mask M can be omitted.

  Since the etching process proceeds only in the portion where the plasma is generated, when the size of the electric circuit element 40 and the line width of the pattern are approximately the same size, the electric circuit element 40 where the plasma P is to be generated. By controlling the above, it is possible to form a pattern without a mask.

  FIG. 4 is a diagram showing a plasma generation unit 100 according to a first modification of the plasma generation unit. The plasma generating unit 100 includes a dielectric plate 101 formed in a hemispherical shape, concave portions 102 provided in a matrix on the lower surface side of the dielectric plate 101, and electric circuit elements provided in the concave portions 102, respectively. 103. The electric circuit element 103 is configured similarly to the electric circuit element 40 described above.

  By using the plasma generating unit 100 configured as described above, it is possible to perform an etching process or the like on a hemispherical target object. Further, by controlling the generation of plasma, the present invention can be applied to a case where the object to be processed is flat.

  FIG. 5 is a view showing a plasma generation unit 110 according to a second modification of the plasma generation unit. The plasma generation unit 110 includes a dielectric plate 111 formed in a cylindrical shape, recesses 112 provided in a matrix on the inner wall surface of the dielectric plate 111, and electric circuit elements 113 provided in the recesses 112, respectively. And. The electric circuit element 113 is configured in the same manner as the electric circuit element 40 described above.

  By using the plasma generation unit 110 configured in this way, it is possible to perform an etching process or the like on a rod-shaped object to be processed.

  The present invention is not limited to the above embodiment. That is, in the above-described embodiment, an example of an antenna in which the conductor line 41 and the capacitor 42 are connected is shown, but the present invention can be applied even when the capacitor 42 is not used. The shape of the conductor line 41 is not necessarily a coil, and may be a straight line, a curved line, or a three-dimensionally complicated shape. Moreover, although dry etching for manufacturing semiconductor devices has been shown as an example, the present invention is not limited to this and can be applied to plasma ashing, plasma CVD, plasma sputtering, plasma cleaning, etc. It is also effective for plasma processing and plasma processing for the purpose of processing a thin film element on a liquid crystal panel or painting a flat surface or curved surface. Of course, various modifications can be made without departing from the scope of the present invention.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

  According to the present invention, when applied to an etching apparatus or the like, the mask thickness can be reduced even if the selectivity to mask etching is small, the pattern can be miniaturized, and the in-plane uniformity of the etching rate can be achieved. Can be kept good.

1 is a cross-sectional view schematically showing an etching apparatus in which a plasma generation apparatus according to an embodiment of the present invention is incorporated. The perspective view which shows the plasma generation part integrated in the plasma generation apparatus from the downward direction. The perspective view which expands and shows the principal part of the plasma generation part. The perspective view which shows the 1st modification of the plasma generation part. The perspective view which shows the 2nd modification of the plasma generation part.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Etching apparatus (plasma generator), 20 ... Chamber, 30 ... Plasma generating part, 40 ... Electric circuit element (plasma generating electrode), 50 ... Switching circuit, 52 ... Power supply, 60 ... Lower electrode, 63 ... Power supply, P: Plasma, M: Mask.

Claims (5)

In a plasma generating apparatus that generates plasma by generating an induced electric field in a container,
A member disposed in the container and disposed opposite to the object to be processed having a plurality of processing regions;
A plasma generating apparatus, wherein a plurality of plasma generating electrodes respectively corresponding to the plurality of processing regions are formed on the object to be processed side of the member.   2. The plasma according to claim 1, wherein the plasma generating electrode includes a recess formed in the member and having an opening on the object side, and a conductor provided on a bottom surface side of the recess. Generator.   The plasma generating apparatus according to claim 1, wherein the member is formed at least over a region wider than the object to be processed.   The plasma generating apparatus according to claim 1, wherein the member is formed to be relatively movable along the surface direction with respect to the object to be processed. In a plasma generation method for generating plasma by generating an induction electric field in a container,
A positioning step arranged opposite to the object to be processed having a plurality of processing regions arranged in the container;
A plasma generation method comprising: a plasma generation step of generating a plurality of plasmas by a plurality of plasma generation electrodes formed on the object side of the member and corresponding to the plurality of processing regions, respectively.

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