JPH087627Y2 - Plasma processing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a plasma processing apparatus for processing a wafer, which is a material of a semiconductor element, by plasma etching or the like. [Prior Art] A wafer is subjected to processing such as plasma etching in the process of manufacturing a semiconductor device. In the plasma etching process, a wafer is placed on one of the electrodes provided opposite to each other in an airtight processing chamber, and a high-frequency voltage is applied between the electrodes in a low-pressure reactive gas atmosphere with the wafer placed. Is applied to generate plasma,
An etching process is performed by the energy of this plasma. A conventional plasma processing apparatus is shown in FIG. Reference numeral 1 is a vacuum container, and 2 is a lid. The upper electrode 3 and the lower electrode 4 are provided on the bottom of the lid 2 and the vacuum container 1 in a state of being insulated by the insulating materials 5 and 6, respectively. Cooling plates 7 and 8 are provided on the back side of both electrode plates 3 and 4, and cooling water is circulated in the flow paths of the cooling plates 7 and 8 to cool both electrode plates 3 and 4. . The upper electrode 3 has a hollow structure, and a large number of gas blowout holes 9 are formed in the lower surface thereof, so that the reaction gas is dispersed and blown out from the gas blowout holes 9. Further, although not specifically shown, the lower electrode 4 has a structure capable of electrostatically attracting a wafer. A gas exhaust port 10 communicating with an exhaust pump (not shown) is provided at a required position around the lower electrode 4 of the vacuum container 1, and the reaction gas blown out and dispersed from the gas blowing hole 9 is exhausted from the gas exhaust port 10. It is adapted to be discharged downward from the outlet 10 through the exhaust pipe 12. In the figure, 11 is a wafer. In plasma processing, in order to uniformly process a wafer, the flow distribution and concentration distribution of the reaction gas inside the processing chamber must be uniform. Therefore, the structure is such that the gas ejected from the upper electrode is dispersed and exhausted through a plurality of gas outlets 10 on the opposite bottom surface. [Problems to be solved by the invention] However, since the exhaust port 10 is provided around the lower electrode 4 and is discharged downward by the exhaust pipe 12, the lower part of the vacuum container 1 is the exhaust pipe 12 and the exhaust pipe. A large space is required for the process of 12, and the space that must be secured for installing the vacuum container 1 is also large, and the installation position of the equipment equipped as the plasma generator is also greatly restricted. ing. Further, since the discharge port 10 must be provided avoiding the lower electrode, there is a problem that a large opening area cannot be obtained, and there is a limit in reducing exhaust resistance and it is difficult to obtain a large exhaust amount. . The present invention has been made in view of such a situation, and exhaust is discharged to the side of the vacuum container, so that space restrictions can be eliminated and the opening area of the exhaust port can be made sufficiently large. It is intended to provide a plasma processing apparatus that is easy to manufacture. [Means for Solving the Problems] According to the present invention, the inside of a vacuum container is divided into a processing chamber including a lower electrode and a donut-shaped duct chamber below the lower electrode by an exhaust dispersion plate provided around the lower electrode. A lower electrode unit surrounded by an insulating material is formed except for the upper surface of the lower electrode, and the lower electrode unit is surrounded by a cylindrical electrode cover to define a duct chamber around the lower electrode unit, and the exhaust gas is exhausted. A required number of dispersion holes are formed in the dispersion plate, an exhaust port communicating with the duct chamber is provided in the vacuum vessel wall, and the reaction gas is introduced into the processing chamber and discharged from the exhaust port. It is a feature. [Operation] The reaction gas introduced into the processing chamber is turned into plasma, dispersed after the reaction by the dispersion holes of the exhaust dispersion plate, flows into the duct chamber, and is discharged from the exhaust port to the outside of the vacuum chamber. [Embodiment] An embodiment of the present invention will be described below with reference to the drawings. The airtight chamber of the vacuum container 14 is defined by the upper lid 15,
An upper electrode 16 is attached to the bottom surface of the lower electrode 15, and the upper electrode 16 is cooled by a required means (not shown). A lower electrode unit 17 is provided on the bottom surface of the vacuum container 14 so as to face the upper electrode 16. In the lower electrode unit 17, an insulating material 19 is attached to the vacuum container 15 via a supporting portion 18, a lower electrode 21 is attached to the insulating material 19 via a cooling plate 20, and further around the lower electrode 21. A cover ring 22 made of a quartz material is provided and configured. A cylindrical electrode cover 23 surrounding the lower electrode unit 17 is erected on the bottom surface of the vacuum container 14. The electrode cover 14
A donut-shaped exhaust dispersion plate 24 is fixed to the upper end of the. The exhaust dispersion plate 24 is provided with a required number of dispersion holes 25 along the circumference. Thus, the processing chamber 26 is located above the exhaust dispersion plate 24.
And a duct chamber 27 is defined below the exhaust dispersion plate 24 and around the electrode cover 23. A reaction gas introducing port 28 is formed in the side wall of the vacuum container 14 above the exhaust dispersion plate 24, and an exhaust port 30 communicating with the duct chamber 27 is formed below the exhaust dispersion plate 24. The exhaust port 30
Is connected to an exhaust pipe (not shown). The operation will be described below. When the reaction gas 29 is introduced from the reaction gas introduction port 28,
The particles are diffused in the processing chamber 26 and are made into plasma to be surface-treated. Next, the exhaust gas flows into the duct chamber 27 through the dispersion holes 25 around the lower electrode 21, is further collected in the exhaust port 30, and is discharged to the outside of the vacuum container 14. As described above, since the dispersion holes 25 are provided in a dispersed manner around the lower electrode 21, the surface treatment of the object to be treated can be performed uniformly without causing a non-uniform flow in the flow of the reaction gas. Further, structurally, since the positions where the reaction gas inlet 28 and the exhaust port 30 are provided are the wall portions of the vacuum container 14, the plasma processing device must be provided above and below the vacuum container 14. You can freely install equipment that does not become,
Further, the positions of the reaction gas introduction port 28 and the exhaust port 30 in the circumferential direction may be arbitrary positions, so that the design restrictions are greatly relaxed. Further, by making the shape of the discharge port flat in the horizontal direction, a sufficient opening area can be obtained. Although the reaction gas inlet is provided in the side wall of the vacuum container in the above embodiment, it goes without saying that it may be provided in the upper electrode as shown in the conventional example of FIG. [Advantage of the Invention] As described above, according to the present invention, the exhaust of the reaction gas is discharged from the side of the vacuum container, so that the lower part of the vacuum container can be used for equipment installation, and the device can be downsized. In addition, simplification can be achieved, design restrictions can be greatly relaxed, and the opening area of the discharge port can be made sufficiently large, so that a large displacement can be obtained, which is an excellent effect.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG. 2 is a sectional view of a conventional example. 14 is a vacuum container, 16 is an upper electrode, 17 is a lower electrode unit, 21 is a lower electrode, 24 is an exhaust dispersion plate, 25 is a dispersion hole, 27 is a duct chamber,
28 is a reaction gas inlet, and 30 is an exhaust port.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kazumasa Makiguchi             2-1-1 Shinmeidai, Hamura-cho, Nishitama-gun, Tokyo             Kokusai Electric Co., Ltd. Hamura Factory              (56) References Japanese Patent Laid-Open No. 63-227021 (JP, A)               JP 63-141318 (JP, A)               JP-A-61-29126 (JP, A)               JP-A-1-258428 (JP, A)               Actual development Sho 63-50127 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. An exhaust dispersion plate provided inside the vacuum container around the lower electrode divides the processing chamber including the lower electrode into a donut-shaped duct chamber below the lower electrode, and insulates except the upper surface of the lower electrode. A lower electrode unit surrounded by a material, the lower electrode unit is surrounded by a cylindrical electrode cover to define a duct chamber around the lower electrode unit, and a required number of dispersion holes are formed in the exhaust dispersion plate. The plasma processing apparatus is characterized in that an exhaust port communicating with the duct chamber is provided in the wall of the vacuum container, and the reaction gas is introduced into the processing chamber and discharged from the exhaust port.