JPS6110239A - Semiconductor manufacturing equipment - Google Patents

Abstract

PURPOSE:To enable dry etching in the optimum state by changing over a change-over switch at each time of sputter etching of a target on a wafer and plasma etching for removal of a deposited organic substance on the inner surface of a chamber. CONSTITUTION:At the time of reactive sputter etching of the target on the wafer 7, an anode plate 4 is changed over to the ground state by the change- over switch 8 into a self-bias state by the difference between the total area of the chamber 1 and the anode plate 4 and the area of a cathode 5, thus enabling anisotropic reactive sputter etching. In the case of removing an organic substance such as resist deposited on the inner surface of the chamber 1 by means of O2 plasma etching, the areas of the opposed electrode plates are equalized by changing the anode plate 4 over to the non-ground state, thus eliminating the self-bias; then, the deposited organic substance on the whole inner surface of the chamber 1 can be effectively removed.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to semiconductor manufacturing equipment, and in particular, for example, in a reactive spasoter/soching equipment, it is possible to efficiently perform processing, ching, and removal of organic matter adhering to the inner surface of a chamber. It is something.

BACKGROUND OF THE INVENTION When manufacturing semiconductor devices, it is necessary to etch insulating films and conductive films. Conventionally, for these etchings, a process such as hydrofluoric acid or nitric acid, or a tinde solution is used.

So-called sea urchin etching was the mainstream, but it was troublesome to prepare the etching solution, leakage occurred, and it was difficult to wash with water.
Because there are problems such as the need for drying and treatment of waste liquid,
Recently, so-called dry etching methods such as gas etching, plasma etching, sputter etching, and ion beam etching have been adopted. In particular, reactive sputter etching, also called reactive ion etching equipment (R, 1, E), is capable of anisotropic etching.
Awarded for manufacturing LSI and VLSH.

FIG. 4 shows a conceptual cross-sectional view of a conventional reactive sputter etching apparatus. In the figure, 1 is a chamber made of aluminum or the like, which is grounded.

This chamber 1 includes an introduction pipe 2 for introducing a reaction gas,
An exhaust pipe 3 for evacuation is connected. Further, in the chamber 1, an anode plate 4 and a cathode plate 5 having approximately the same area are arranged facing each other, the anode plate 4 is grounded, and a high frequency A power source 6 is connected.

In the above configuration, for example, S on the Sl wafer 7
To explain the case of forming a window hole in an iO, film using a photoresist, first, the above-mentioned wafer 7 is placed on the cathode plate 5, and the interior of the chamber 1 is 10' The pressure is reduced to approximately IQ' TOrr, and CF is introduced as a reaction gas from the introduction pipe 2.

/ Introduce Hl and connect the high frequency power supply 6. Then,
Chamber 1, anode plate 4, and cathode plate 5
Due to the difference in area between the two, a self-bias is generated and a discharge occurs, and the Sin film exposed through the window hole of the resist of the wafer 7 placed in this discharge area is activated by the Fuji force/L. ' Anisotropically etched by F4 and ions.

Problems to be Solved by the Invention By the way, the above-mentioned reactive sputter etching apparatus has a problem in that during sputtering, the target object S10. However, some of the resist used as a mask material is sputtered and adheres to the inner surface of the chamber 1.

Therefore, every time a predetermined number of wafers 7 are processed,
O2 is introduced into the chamber 1 as a reactive gas to remove the resist attached to the inner surface of the chamber 1. Removal with plasma is performed.

However, if the chamber 1 is grounded as described above, a self-bias is applied even during O plasma, and anisotropic plasma etching is performed, so the resist on the entire inner surface of the chamber 1 cannot be removed efficiently, and There was a problem in that it took a very long time to remove the resist, and the operating rate of the apparatus deteriorated.

Means for Solving the Problems This invention provides a chamber whose at least inner surface is made of a conductive material and is grounded, and anode electrodes having approximately the same area and facing each other and electrically connected to the chamber. a high frequency power source connected between the plate and the cathode plate, and the anode plate and the cathode plate;
The apparatus is provided with a changeover switch for switching the electric sword-like connection state of the anode plate and the cathode plate.

According to the above means, when performing reactive sputter etching of an object on a wafer, the anode plate is switched to the grounded state by the changeover switch, and the sum area of the chamber and the anode plate is equal to the area of the cathode plate. Depending on the difference in the irradiance, a self-bias state can be established and anisotropic reactive sputter etching can be performed. In addition, when removing organic matter such as 1/cyst attached to the inner surface of the chamber by OI plasma etching, switch the anode plate to an ungrounded state, make the areas of the opposing plates equal, and self-bias. isotropic 0. Plasma etching makes it possible to efficiently remove organic matter adhering to the entire inner surface of the chamber.

Embodiment FIG. 1 shows a cathode-coupled reactive substrate, Sotae 1, which is an embodiment of the present invention. 1 shows a conceptual cross-sectional view of the cutting device.

It is the same as FIG. 4 except for the following points, and corresponding parts are given the same reference numerals and their explanations will be omitted. The difference from FIG. 4 is that the chamber 1 and the anode plate 4 are electrically insulated via an insulator, and the other end of the high frequency power source 6 and the anode plate 4 are directly connected, and A switch 8 is inserted between the connection point between the two and the ground.

In the above configuration, when etching the anisotropically reactive substrate of StO+ on the wafer 7, as shown in FIG. Then, the anode plate 4 is grounded, and the ground electrode area between the anode plate 4 and the chamber 1 becomes larger than the high frequency application electrode area of the cathode plate 5, so that the self-bias is increased. Hanging,
The S10 film on wafer 7 is removed by anisotropic reactive sputter etching.

On the other hand, when removing organic materials such as resist attached to the inner surface of the chamber 1, as shown in FIG. 3, Ol is introduced into the chamber 1 and the switch 8 is opened. Then, the anode plate 4 becomes a non-grounded part, and since the areas of the anode plate 4 and the cathode plate 5 are the same, no self-bias is applied, and the isotropic Olodesma etching is performed. Adhering organic matter on the inner surface of the chamber 1 is removed.

Note that although the above embodiments have been described with respect to a cathode-coupled type, the same can be applied to an anode-coupled type.

In some cases, the switch 8 may be opened when etching reactive spots or vines of the target on the wafer 7.
You can also perform isotropic suba, sotae, and notching.

Effects of the Invention As described above, the present invention provides spa J of an object on a wafer.
Zero organic matter adhering to the inner surface of the chamber during tae-soching
．． When dry etching and notching, change the selector switch to perform dry etching at the optimum shape, respectively.
In particular, since attached organic matter can be efficiently removed in a short time, the operating rate of the apparatus can be improved.

[Brief explanation of the drawing]

FIG. 1 is a conceptual cross-sectional view of a reactive sprocket etching apparatus according to an embodiment of the present invention, FIG. 2 is a conceptual cross-sectional view of the state during anisotropic etching of an object on a wafer, and FIG. FIG. 3 is a conceptual cross-sectional view of the state of the attached organic matter during isotropic etching. FIG. 4 is a conceptual cross-sectional view of an example of a conventional reactive nupanotaenoting device. l...--Chamber, 4... Anode plate, 5... Cathode plate, 6... High frequency power supply, 8... Changeover switch. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] a chamber having at least an inner surface formed of a conductive material and grounded; an anode electrode plate and a cathode electrode plate having substantially the same area and facing each other and electrically insulated from the chamber; A semiconductor manufacturing device comprising a high frequency power source connected between cathode plates, and a changeover switch for switching the electrical connection state of the anode plate and the cathode plate.