JP2000357677A - Semiconductor treating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize uniform etching of a large-sized wafer. SOLUTION: This semiconductor treating apparatus comprises upper and lower electrodes 13, 12 in a treating tank 11 and a gas feeder 20 for feeding a process gas in the treatment tank 11, to generate a plasma between the electrodes 12, 13 for treating a semiconductor sample 15. The gas feeder 20 comprises an approximately cylindrical central distributor 21, having rows of specified holes 21a at the sidewall and a peripheral distributor 22 which is slidably housed with center at the central distributor 21 and has many gas passages 22a communicate with the outer surface from positions adjacent the central distributor 21. The relative position of the central distributor 21 to the peripheral distributor 22 is changed to cause the holes 21a of the central distributor 21 to communicate with the gas passages 22a of the peripheral distributor 22 according to a recipe, thereby feeding the process gas introduced into the central distributor 21 from the outer wall of the peripheral distributor 22 into the treatment tank 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor processing apparatus for processing a semiconductor sample using plasma, and more particularly to an etching apparatus or an ashing apparatus in semiconductor manufacturing.

[0002]

2. Description of the Related Art In semiconductor manufacturing, the most difficult problem when the diameter of a wafer is increased is to realize uniform etching over the entire wafer. This is because there is an unavoidable non-uniformity in that there is abundant supply of biproducts (etching products) in the middle of the wafer, but there is no object to be etched outside at the wafer edge. As a countermeasure, there is a method of blowing gas toward the wafer center,
In this case, even if it is effective for one process or structure, there is a high possibility that it will adversely affect other processes or structures. In particular, when a single device is used to process a contact hole, a wiring or a groove, and to etch a different structure, a problem easily occurs.

[0003]

The most important thing in a large-scale etching apparatus is to ensure uniformity. The most important and difficult parameter for determining the uniformity is the gas introduction method. There are various methods of supplying gas from the top and from the side, but it is difficult to determine an introduction method with a wide margin that can be applied to all processes. In particular, if the aperture ratio of the object to be etched greatly changes, the deposition properties of the center and the etch change, making it difficult to obtain uniformity, especially for a large-diameter wafer.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has at least one or more processes and structures, for example, a contact structure in which the surface of a wafer is almost covered with a resist and a half of the etching area. An object of the present invention is to etch both of the above wiring structures while ensuring uniformity. Another object is to realize uniform etching of a large-diameter wafer. Further, the present invention can make the method of supplying gas variable in a recipe, and expands a margin for adjusting uniformity.

[0005]

A semiconductor processing apparatus according to the present invention includes an upper electrode and a lower electrode in a processing tank.
A gas supply for supplying a process gas into the processing tank is provided, and plasma is generated between the two electrodes to process a semiconductor sample. This gas supply device has a center distributor having a substantially cylindrical shape and a row of predetermined holes provided around the center distributor, and slidably received around the center distributor. A peripheral distributor formed with a number of gas paths communicating therewith. Then, by changing the mutual position of the central distributor and the peripheral distributor, the row of holes of the central distributor and the gas path of the peripheral distributor are communicated according to a recipe, and the central distributor is provided. Is supplied from the outer periphery of the peripheral distributor into the processing tank. This makes it possible to perform uniform etching on a large-diameter wafer.

According to another aspect of the present invention, in the semiconductor processing apparatus, the center distributor defines a plurality of types of rows of holes along the length direction corresponding to the recipe, and the center distributor is provided according to the recipe. Is rotated to select the gas path of the peripheral distributor communicating with the row of holes of the central distributor.

According to another aspect of the present invention, in the semiconductor processing apparatus, the center distributor defines a plurality of types of rows of holes along a circumferential direction corresponding to the recipe. Is moved up and down to select the gas path of the peripheral distributor communicating with the row of holes of the central distributor.

According to another aspect of the present invention, in the semiconductor processing apparatus, the peripheral distributor defines a plurality of types of combinations of gas paths corresponding to the recipe, and the peripheral distributor distributes the gas from the processing tank according to the recipe. This is to control the distribution of the process gas supplied therein.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same or corresponding parts have the same reference characters allotted, and description thereof may be simplified or omitted.

FIG. 1 is a sectional view showing a schematic structure of an etching apparatus according to an embodiment of the present invention. As shown in FIG. 1, the etching apparatus 10 includes a chamber 11 (processing tank), a lower stage 12 serving as a lower electrode provided in a lower part of the chamber, an upper electrode 13 provided in an upper part of the chamber, A control unit 14 disposed below the stage 12. Lower stage 1
A wafer 15 (semiconductor sample) is placed on 2.
The control unit 14 includes a power introduction mechanism, an electrostatic chuck, a wafer up / down mechanism, a wafer temperature control mechanism, and the like. A gas supply unit 20 (gas introduction unit), which is a feature of this embodiment, is disposed below the upper electrode 13.

In this embodiment, a gas for generating plasma is introduced from the gas supply unit 20 into the processing tank 10 at a flow direction and an initial speed according to the recipe. Discharge is generated in the chamber 11 by power introduction from the upper electrode 13 or the antenna, and plasma is generated. The wafer 15 mounted on the lower stage 12 is etched by the plasma gas.

FIG. 2 is a view for explaining an example of the gas supply section 20 in this embodiment. As shown in FIG. 2, the gas supply device 20 includes a central distributor 21 that is substantially cylindrical and located at the center, and a hemispherical peripheral distributor 22 that houses the central distributor 21 at the center. The central distributor 21 is provided with a large number of holes 21a provided on the cylinder surface according to a predetermined rule. The peripheral distributor 22 is provided with a large number of gas paths 22a communicating outward from a position facing the hole 21a of the central distributor 21. When the holes 21a of the central distributor 21 and the holes 22a of the peripheral distributor 22 are placed in a specific mutual positional relationship, the selected group of holes 21a communicates with the selected group of holes 22a,
It is designed to conduct gas from the inside to the outside.

The process gas is supplied to the process gas supply 20
The gas is supplied from the upper part of the chamber to the center distributor 21 (center part) of the (gas supply kit). The inside of the center distributor 21 is basically hollow, although there are some measures to reduce the volume. The center distributor 21 is a rotatable mechanism.
Or a hole 2 of the type corresponding to the number of recipes, such as β
Row 2a is repeatedly opened.

Gas supply unit (process gas supply kit) 2
It can be seen that many gas paths 22a are machined in the peripheral distributor 22 of No. 0 as shown in the sectional view. The number of machining of this path basically corresponds to the number of repetitions of the row of holes. For example, as shown in FIG. 2, when four types of holes are repeatedly processed four times, the same cross section is obtained at a portion rotated by 90 degrees. As shown in FIG. 2, it is also possible to widen the outlet at the end of the gas path 22a of the peripheral distributor 22 to reduce the initial velocity of the gas.

FIG. 3 is a sectional view showing an example of another gas supply device (gas supply kit) according to this embodiment. In this example, the central distributor 21 moves up and down with respect to the peripheral distributor 22, and this operation changes the combination in which the hole 21a of the central distributor 21 communicates with the gas path 22a of the peripheral distributor 22. It is. In the position shown in FIG. 3, of the holes 21 a of the central distributor 21, those of level z are in communication with the gas path 22 a of the peripheral distributor 22. Now, when the position of the center distributor 21 is slightly lowered, the hole 21a at the position of the level x in the drawing communicates with the gas path 22a of the peripheral distributor 22 to introduce gas.
The gas is introduced from the hole (path) at the position.

In the above example, it has been described that the center distributor 21 is formed with holes for determining two or more types of gas introduction paths. However, the peripheral distributor 22 may be provided with two or more types of gas introduction paths. It is possible. That is, the path changes when looking at cross sections at different angles.

Next, a specific example when the etching apparatus of this embodiment is used will be described. As an etching apparatus, an example of an ICP type oxide film etching apparatus for a 300 mm wafer will be described. An example of the etching conditions is as follows. Pressure: 40mTorr, Gas flow rate: C4F8 = 50sccm, Ar = 300sccm, CO = 200sccm, O2 =
30sccm power: upper electrode 3000W (13.56MHz), lower electrode 1000W
(400kHz) Gap: 15cm For example, if the etch stop is likely to occur because the contact pattern is almost completely covered with the resist and the depot property is too strong at the center of the wafer, the gas directivity path to the wafer center ( For example, a hole in the column α in FIG. 2) is designated by the recipe. On the other hand, in the case of damascene grooving in which the deposition property is small and the uniformity of the etch rate is important, a path capable of supplying a uniform gas over the entire surface of the wafer (for example, row β in FIG. 2).
Hole) is specified in the recipe.

As described above, in this embodiment, a gas supply device (gas supply kit) is provided at the center of the upper electrode or the upper plate, and the gas supply device is provided therefrom according to the recipe.
The process gas is supplied to the chamber by the above methods (flow direction and directivity). In order to realize a plurality of gas flows, a gas distributor (gas supply kit) is a hollow distributor having a central distributor 21 having a large number of holes and a peripheral distributor 22 having a plurality of gas introduction paths. The center distributor 21 is rotated or moved up and down to a specified position according to a recipe, so that gas is chambered from a portion where the position of the hole 21a of the center distributor 21 matches the position of the gas path 22a of the peripheral distributor 22. Release into.

In general, there are many by-products at the center of the wafer, and the center of the wafer has a stronger depot property than, for example, the wafer edge portion. The best way to reduce this effect is to spray a fresh process gas toward the center of the wafer, but this can be achieved by using a recipe with many gas paths towards the wafer center in this structure. In other words, a gas with a flow rate of a certain level or more is supplied to the wafer center, so that a gas with a component with a strong depot property with a large proportion of bi-products is driven out, replaced with fresh gas, and the gas with the wafer edge is replaced. Can be reduced. On the other hand, if it is difficult to make a difference between the center and the edge, and if it is easier to make the center and the edge flow gas more uniform, a recipe that can uniformly supply the gas to the center and the edge is selected.

As described above, in this embodiment, the gas supply unit (gas supply kit) is provided at the center of the upper plate of the processing apparatus such as an etching apparatus, and the ratio of supply to the wafer center is increased. A mechanism is provided that makes it possible to change the flow of a gas that changes from one with a higher ratio to one with a higher directivity (flow velocity) to one with a lower directivity. Process gas is a gas supply (gas supply kit)
The gas is introduced from the back side of the upper plate into the central distributor (center portion) of the gas supply device. There are many holes in the central distributor (center), and the central distributor (center)
Is rotated or moved up and down so that the gas flows in accordance with the corresponding gas introduction path of the peripheral distributor. This rotation or up and down movement can be changed by the recipe. Thus, even when the etching pattern on the wafer surface is significantly different, it is possible to uniformly etch the entire wafer surface accordingly. In addition, uniform etching can be performed on a large-diameter wafer.

[0021]

Since the present invention is configured as described above, it has the following effects. (1) The uniformity of the etching rate in the wafer can be improved. (2) The uniformity of the etching selectivity in the wafer can be improved. (3) The uniformity of the etched shape in the wafer can be improved. (4) The macro loading effect can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a schematic structure of an etching apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a gas supply unit according to the embodiment.

FIG. 3 is a cross-sectional view showing an example of another gas supply device of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Etching apparatus 11 Chamber (processing tank) 12 Lower stage (lower electrode) 13 Upper electrode 14 Control part 15 Wafer (semiconductor sample) 20 Gas supply part (gas introduction part) 21 Central distributor 21a hole 22 Peripheral distributor 22a Gas path

Claims (4)

[Claims] 1. A semiconductor processing apparatus comprising an upper electrode and a lower electrode in a processing tank and generating a plasma between the two electrodes to process a semiconductor sample, wherein a substantially cylindrical row of predetermined holes is provided around the semiconductor processing apparatus. A central distributor provided slidably about the central distributor, and a peripheral distributor formed with a number of gas paths leading to an outer surface from a position in contact with the central distributor. By changing the mutual position of the dispenser and the peripheral distributor, the row of holes of the central distributor and the gas path of the peripheral distributor are communicated according to the recipe, and the process introduced into the central distributor is performed. A semiconductor processing apparatus, comprising: a gas supply device that supplies a gas from an outer periphery of the peripheral distributor into the processing tank. 2. A plurality of types of rows of holes along the length direction corresponding to the recipe are defined in the center distributor, and the center distributor is axially rotated according to the recipe, thereby obtaining the center distribution. 2. The semiconductor processing apparatus according to claim 1, wherein a gas path of the peripheral distributor communicating with a row of holes of the vessel is selected. 3. The center distributor is provided with a plurality of types of rows of holes along the circumferential direction corresponding to the recipe, and the center distributor is moved up and down in accordance with the recipe, so that the center distribution is performed. 2. The semiconductor processing apparatus according to claim 1, wherein a gas path of the peripheral distributor communicating with a row of holes of the vessel is selected. 4. In the peripheral distributor, a plurality of types of combinations of gas paths are defined corresponding to recipes, and distribution of process gas supplied from the peripheral distributor into the processing tank in accordance with the recipe is defined. 2. The semiconductor processing apparatus according to claim 1, wherein the semiconductor processing apparatus is controlled.