JP3052266B2 - Plasma processing method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing method , and more particularly to a plasma processing method suitable for etching a wafer one by one by a dry process. is there. 2. Description of the Related Art As a semiconductor manufacturing apparatus for etching a wafer by a dry process, a batch type semiconductor manufacturing apparatus for simultaneously etching a plurality of wafers has been dominant. However, miniaturization of semiconductor integrated circuit elements,
As the degree of integration and the diameter of a wafer increase, the requirements for performance such as uniformity of etching become more severe, and a batch type semiconductor manufacturing apparatus can no longer respond to this requirement. Therefore, as a semiconductor manufacturing apparatus that satisfies this requirement, a single-wafer type semiconductor manufacturing apparatus that performs an etching process on a wafer one by one in a dry process has been developed and has been widely used in recent years. On the other hand, techniques for etching a wafer by a dry process (hereinafter abbreviated as dry etching technique) include a reactive sputter etching technique and a microwave plasma etching technique. Various characteristics of these dry etching techniques have been elucidated to a large extent recently, and some of them have been put to practical use. However, each of these dry etching techniques has advantages and disadvantages, and its application range is limited. [0004] Conventional single-wafer semiconductor manufacturing can respond to performance demands such as etching uniformity due to miniaturization and high integration of semiconductor integrated circuit elements and enlargement of wafer diameter as described above. Since the applied range of the dry etching technology used is a single technology that is limited, the etching shape is controlled stepwise, and the etching process is performed in the same equipment, such as performing the processing before and after the etching process continuously in the same device. At present, the diversification of specifications is progressing, and it is no longer possible to cope with them. SUMMARY OF THE INVENTION An object of the present invention is to combine different dry etching techniques to obtain a sample.
An object of the present invention is to provide a plasma processing method capable of finishing an optimum shape for processing a semiconductor element . SUMMARY OF THE INVENTION The present invention provides a plasma processing method for processing a sample one by one with a plasma.
A first step of subjecting the sample to a reactive sputter etching process using ions and radicals in the plasma in a first region provided in the first chamber; and in the plasma generation source region different second region <br/>, a second step of etching said sample by plasma capable shape control of etch angle, wherein the first region second Transports the sample between areas
And a conveying step, by said second step and said first step, characterized in that stepwise control of the etching profile of the sample. According to the present invention, by combining different dry etching techniques , the etching shape is controlled stepwise.
Samples can be processed, making them ideal for processing semiconductor devices.
There is an effect that the shape can be finished. An embodiment of the present invention will be described with reference to FIG. In FIG. 1, the reaction chamber 10 is provided with a container 20 of a reactive sputter etching apparatus as a first etching apparatus and a second etching apparatus as a second etching apparatus so that a combined etching of reactive sputter etching and microwave plasma etching can be performed. A container 30 for the microwave discharge device is provided therein. Reaction chamber 10 and container 30 of microwave discharge device
Means that the exhaust system 11 evacuates the container 20 of the reactive sputter etching apparatus by the exhaust system 12. The reactive sputter etching container 20 includes:
In this case, a high-frequency electrode 21 and a wafer mounting electrode (hereinafter, abbreviated as a table) 22 are provided inside in such a manner as to oppose the vertical direction. The high-frequency electrode 21 has a gas discharge hole (not shown) for discharging an etching gas toward the surface of the table 22,
A gas supply passage (not shown) communicating with the gas discharge hole and supplying the etching gas to the gas discharge hole is formed, and the gas supply passage is connected to gas supply means installed outside the reaction chamber 10, for example, a gas cylinder 23. The connected gas conduit 24 is connected. The high-frequency electrode 21 is connected to a high-frequency power supply 25 installed outside the reaction chamber 10. A single wafer 40 is placed on the table 22 via a sample table 26, and a high frequency power is applied to the high frequency electrode 21 from a high frequency power supply 25. As a result, the etching gas released from the gas discharge holes into the reactive sputter etching container 20 is turned into plasma. The activated neutral molecules and atoms (radicals) and ions in the plasma enter the wafer 40, and as a result, the wafer 40
Has its surface chemically and materially etched. On the other hand, a table 31 is provided in the reaction chamber 10 so as to face the microwave discharge vessel 30, and a permanent magnet 32 is provided below the table 31. At the top wall of the reaction chamber 10, a microwave generator 3
The other end is connected in a state where the waveguide 34 provided with 3 surrounds the microwave discharge vessel 30. Waveguide 34
A magnetic field generating coil 35 is provided on the outer periphery of the microwave discharge vessel 30, and the microwave discharge vessel 30 communicates with a discharge space 36 of the microwave discharge vessel 30, and is provided with gas supply means provided outside the reaction chamber 10, for example, , A gas conduit 38 connected to a gas cylinder 37 is connected. A single wafer 40 is placed on the table 31 via a sample table 39, and an etching gas is introduced into the discharge space 36 from a gas cylinder 37. The etching gas introduced into the discharge space 36 has a mirror magnetic field formed in the discharge space 36 by the magnetic field generating coil 35 and the permanent magnet 32 and a waveguide 34 generated by the microwave generator 33.
Is converted into plasma by a synergistic action with a microwave electric field formed in the discharge space 36 by the microwave propagated in the step (a). The active ions in the plasma are incident on the wear 40 along the mirror magnetic field, so that the surface of the wafer 40 is etched. Although not shown in FIG. 1, in this case, the wafer 40 can be transported between the reactive sputter etching container 20 and the microwave discharge container, and the wafer 40 can be loaded and unloaded between the reaction chamber 10 and the outside. It has a simple structure. The case where single crystal silicon used for a gate film of a semiconductor memory element is etched by such an apparatus will be described below. The performance of the dry etching technique is greatly affected by its etching reaction mechanism. In reactive sputter etching technology, the etching rate is fast,
However, electrical damage due to ions is large. On the other hand, the microwave plasma etching technology is extremely excellent in fine workability, such as being small in electrical damage due to ions and capable of controlling the shape such as an etching angle. However, the etching speed is small and the mass productivity is extremely low. Inferior. Therefore, by performing etching in the following order, the advantages of both etching techniques can be maximized. In other words, in the first stage of the etching, 70 to 150
80% is etched, and then the remaining 20 to 30% of single crystal silicon is etched in a second stage by a microwave plasma etching technique. Thus, etching can be performed at a high etching rate without causing electrical damage to the semiconductor element. Further, by controlling the etching shape stepwise, it is possible to finish the semiconductor device in an optimum shape for processing. FIG. 2 shows another first embodiment of the present invention. In a processing chamber 10 ', two reactive sputter etching vessels 20 and one microwave discharge vessel 30 are provided. . In FIG. 2, the same devices and the like as those in FIG. In such a semiconductor manufacturing apparatus, it is possible to further respond to diversification of required etching specifications by adopting an optimal dry etching technique for each of a plurality of stages of etching of a wafer. FIG. 3 shows a second embodiment of the present invention. In the processing chamber 10 ", one reactive sputter etching container 20 and two microwave discharge containers 30 are provided. In Fig. 3, the same devices as those in Fig. 1 are denoted by the same reference numerals, and description thereof is omitted, and in such a semiconductor manufacturing device, the effects obtained in the first embodiment can be obtained. FIG. 4 shows a third embodiment of the present invention. A table 50 in which the tables 22 and 31 shown in FIG. 1 are integrated is rotatably provided in the processing chamber 10. In Fig. 4, the same devices as those shown in Fig. 1 are denoted by the same reference numerals, and description thereof is omitted. Wafer carrying wafers to and from microwave discharge vessel 20 It is possible to simplify the feeding mechanism. [0019] The present invention as has been described above, different de
Combine light etching technology to create an etched shape
Samples can be processed in a step-by-step manner.
There is an effect that it is possible to finish to an optimum shape for the child processing .

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram of a single-wafer semiconductor manufacturing apparatus showing one embodiment of the present invention. FIG. 2 is a configuration diagram of a single-wafer semiconductor manufacturing apparatus showing another embodiment of the present invention. FIG. 3 is a configuration diagram of a single-wafer semiconductor manufacturing apparatus showing another embodiment of the present invention. FIG. 4 is a configuration diagram of a single-wafer semiconductor manufacturing apparatus showing another embodiment of the present invention. [Description of Signs] 10, 10 ′, 10 ″: reaction chamber, 11, 12: exhaust system, 20: reactive sputter etching container, 23,
37: gas cylinder, 25: high-frequency power supply, 30: microwave discharge vessel, 32: permanent magnet, 33: microwave generator, 34: waveguide, 35: coil for generating magnetic field, 40: wafer

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Hideku Fukuhara               794 Kudamatsu-shi, Yamaguchi Prefecture               Hitachi Kasado Plant (72) Inventor Noriyuki Marumoto               794 Kudamatsu-shi, Yamaguchi Prefecture               Hitachi Kasado Plant (72) Inventor Sadayuki Okuhira               1-280 Higashi Koikebo, Kokubunji-shi, Tokyo                 Central Research Laboratory, Hitachi, Ltd.                (56) References JP-A-56-137638 (JP, A)                 JP-A-56-278 (JP, A)

Claims (1)

(57) [Claims] In a plasma processing method of processing a sample one by one with a plasma, a first step of subjecting the sample to a reactive sputter etching process using ions and radicals in the plasma in a first region provided in one chamber If, in a second region different from the plasma generating source of said first region provided in the indoor of the one, a second step of etching said sample by plasma capable shape control of etch angle, the A transporting step of transporting the sample between a first area and the second area , wherein the etching shape of the sample is controlled stepwise by the first step and the second step. A plasma processing method characterized by the above-mentioned.