JP3150400B2 - Dry etching apparatus and dry etching method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dry etching apparatus.

[0002]

2. Description of the Related Art Etching technology for single crystal or polycrystalline silicon (Si) film and Si ₃ N ₄ film by CF 4 gas plasma has already been applied to large scale integrated circuits (LSI).
It has become common as a technique for manufacturing a fine structure such as the above. In this etching technique, a so-called down-flow method is often used in which a processing chamber is provided immediately below a plasma generation chamber and a reaction gas converted into active particles flows downward in order to effectively act on active particles generated by microwave excitation. ing. FIG. 4 shows a conventional general apparatus based on this method. The apparatus has a microwave introduction means (13) provided with a waveguide (12) having a microwave transmission window (11) formed thereon and reactant gas. The plasma generation chamber (15) to which the introduction pipe (14) to be introduced is connected, and this plasma generation chamber
At the boundary with (15), a metal mesh (1
A processing room to which 6) is attached and to which an exhaust pipe (17) is connected
(18) and a cooling means (19) for circulating cooling water inside the side of the plasma generation chamber (15) for cooling. Inside the processing chamber (18), a support (21) for supporting the substrate (20) to be processed is provided. In the above device, the inlet pipe (12)
As shown in the figure, the plasma generation chamber (15) is provided at one location above the plasma generation chamber (15), so that the plasma distribution becomes non-uniform inside the plasma generation chamber (15), so that the active particles The occurrence is also partial.

[0003]

As described above, even if the generation of active particles is partial, there is no particular problem when etching a relatively small area having a diameter of about 15 cm or less. As the size increases, the non-uniformity of the plasma distribution in the chamber becomes a serious problem. Japanese Patent Application Laid-Open No. 3-11725 discloses a technique for relatively moving a supply portion of a reaction gas and an object to be processed. However, even with this movement, a difference occurs in processing between the central portion of the object to be processed and both end portions which are the folded portions, and the problem due to uneven plasma distribution still remains. SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and has as its object to provide a dry etching apparatus that makes plasma distribution uniform in a chamber. [Configuration of the Invention]

[0004]

A microwave generator, a plasma generation chamber into which the microwave and the reactive gas generated from the microwave generator are introduced, and a gas supply for supplying the reactive gas Part, an etching chamber provided so as to be able to communicate with the plasma generation chamber, and a nozzle provided at a boundary between the etching chamber and the plasma generation chamber, wherein the nozzle is a hollow body, a plurality of tubular bodies erected and opened in the above plasma generation unit and the etching chamber at predetermined intervals in the body, the double
A plurality of pores which are provided between the openings of the tubular bodies on the side of the plasma generation chamber and are provided to uniformly supply the reactive gas to the plasma generation chamber of the hollow body; A step of placing an object to be processed in a hermetic container, and reducing the pressure in the hermetic container to a predetermined pressure with a dry etching apparatus having an introduction portion formed in the portion and introducing the reactive gas into the hollow body. A hollow body having a plurality of tubular bodies that are formed in a hollow body and separate the inside of the hermetic container into a plasma generation chamber and an etching chamber, and open to the plasma generation chamber and the etching chamber. the reactive gas is supplied to the reaction gas into the nozzle from the plurality of pores in the plasma generation chamber having formed inside and the plasma generation chamber uniformly plurality of supplying pores of communicating the reactive gas to And supplying the active gas uniformly to the etching chamber through the tubular body, and etching the object to be processed. Since the dry etching is performed, the reaction gas is uniformly supplied into the plasma generation chamber, and a uniform discharge is obtained. As a result, the active particles can be uniformly supplied into the etching chamber to perform uniform processing.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings showing embodiments. FIG. 1 shows a so-called down-flow type microwave plasma etching apparatus according to an embodiment of the present invention. That is, it has a pressure-resistant airtight container (30), and the upper part of the container is formed in a quartz window (32) for passing microwaves by a substantially horizontally supported air-permeable nozzle (31). The plasma generation chamber (33) is divided into an upper side and an etching processing chamber (34) below. Plasma generation chamber (33)
Is formed in a cooling section (35) which forms an annular space, and a supply pipe (3) for supplying cooling water to the cooling section (35).
6), and the drain pipe (37) is connected. A processing table (38) is provided inside the etching chamber (34), and an exhaust pipe (39) connected to a pressure reducing means (not shown) such as a vacuum pump is connected to a side portion. . A waveguide (40) connected to a microwave generation unit (not shown) is attached to the upper part of the plasma generation chamber (33), and the microwave output from the microwave generation unit is used to generate plasma through a quartz window (32). It is designed to be introduced into the room (33).

On the other hand, as shown in FIGS. 2 and 3, the nozzle (31) has a circular container body (43) in which a space (42) having a predetermined depth is formed while leaving an outer peripheral portion of a uniform width. ), A plurality of pipes (44) arranged at a substantially predetermined pitch over the entire space, and a lid that is put on the container (43) so as to cover these pipes (44).
(45). Vent holes (46a) and (46b) communicating with the respective tubes (44) are formed in the bottom of the container (43) and the lid (45) in the space (42). (46)
The plasma generation chamber (33) and the etching chamber (34) communicate with each other via the tube (44). The lid (45) is directed toward the plasma generation chamber (33), and an ejection hole (47) is formed between the ventilation holes (46). Each of these vents (4
7) communicates with a supply hole (48) formed in a part of the side of the container (43) through a space (42) between the pipes (44).

The nozzle (31) is configured as described above, and the ring (50) constituting a part of the airtight container (30) with the lid (45) facing the plasma generation chamber (33). It is airtightly mounted by. A communication hole (51) communicating with the supply hole (48) is formed in the ring body (50), and a reaction gas supply pipe (52) is connected to the communication hole (51).

Next, the operation of the above configuration will be described. After the object to be processed (55) such as a glass substrate is placed on the processing table (38), the inside of the airtight container (30) is evacuated to a high vacuum (10 ^-4 Torr or less), and the reaction gas supply pipe (52) For example, CF ₄ is supplied as a reactive gas. The supplied reaction gas passes through the communication hole (51), the supply hole (48), and the space (4) in the nozzle (31).
Introduced in 2). The introduced reaction gas is supplied to the inside of the plasma generation chamber (33) from the ejection holes (47) almost uniformly.
The supplied reaction gas enters the etching chamber (34) through each of the ventilation holes (46a), the pipe (44) and the ventilation holes (46b).
Further, a predetermined amount is exhausted from the exhaust pipe (39). The inside of the airtight container (30) is maintained at a predetermined pressure by the supply amount from the reaction gas supply pipe (52) and the exhaust amount from the exhaust pipe (39). On the other hand, the microwave generated in the microwave generator is guided to the waveguide (40),
It passes through the quartz window (32) and discharges inside the plasma generation chamber (33). This discharge generates plasma due to the reaction gas and generates active particles. In the process of producing the active particles,
As described above, the reaction gas is almost uniformly supplied from each ejection hole (47) into the plasma generation chamber (33). A uniform discharge is obtained.

[0009]

According to the present invention, the uniform discharge in the plasma generation chamber (33) makes the distribution of plasma uniform, and as a result, active particles are uniformly distributed from the ventilation holes (46b) in the nozzle (30) to the etching processing chamber ( 34), it was possible to achieve a uniform etching process on the object to be processed (55). As a result, it has become possible to realize dry etching of an object to be processed having a large area without complicating the apparatus.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing one embodiment of the present invention.

FIG. 2 is a perspective view of a main part in FIG.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a configuration diagram showing a conventional example.

[Explanation of symbols]

(31) Nozzle, (33) Plasma generation chamber, (34) Etching chamber, (43) Container, (44) Tube, (46) Vent, (47) Outlet, (48) ... supply hole (introduction section).

Continuation of the front page (56) References JP-A-61-272386 (JP, A) JP-A-1-307212 (JP, A) JP-A-60-160620 (JP, A) JP-A-3-129817 (JP) , A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21/3065 C23F 4/00 H05H 1/46

Claims (2)

(57) [Claims] A microwave generation section, a plasma generation chamber into which microwaves and a reactive gas generated from the microwave generation section are introduced, a gas supply section for supplying the reactive gas, and a plasma generation section. An etching chamber provided so as to be able to communicate with the chamber, and a nozzle provided at a boundary between the etching chamber and the plasma generation chamber, wherein the nozzle is provided at a predetermined interval in the hollow body and the hollow body. A plurality of tubular bodies which are provided and open to the plasma generating section and the etching chamber ;
A plurality of pores which are formed between the openings on the side of the plasma generating chamber and are provided to uniformly supply the reactive gas to the side of the plasma generating chamber of the hollow body; A dry gas introduction device for introducing a reactive gas into the hollow body. 2. A step of placing an object to be processed in a hermetic container, a step of reducing the pressure in the hermetic container to a predetermined pressure, and an etching process in which the inside of the hermetic container is formed as a hollow body and a plasma generation chamber is formed. A plurality of tubular bodies that are separated into chambers and open to the plasma generation chamber and the etching processing chamber, and communicate the interior of the hollow body with the plasma generation chamber to uniformly supply the reactive gas. Supplying a reactive gas to the inside of a nozzle having a plurality of pores to supply a reactive gas from the plurality of pores to the plasma generation chamber; generating a plasma by reacting the reactive gas to generate active particles; And etching the object to be processed by uniformly supplying the object to the etching chamber through the tubular body.