JP3403973B2 - Semiconductor processing equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention uses a plasma.
The present invention relates to a semiconductor processing apparatus for processing a semiconductor wafer , and is particularly applied 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 a wafer has a large diameter is to achieve uniform etching over the entire wafer. This is because there is an abundant supply of bi-products (etching products) in the middle of the wafer, while there is an unavoidable non-uniform element at the wafer edge where there is no object to be etched outside. 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, it is likely to adversely affect another process or structure. In particular, when a single device is used to process contact holes, wiring and trenches, and when etching different types of structures, problems can easily occur.

[0003]

The most important thing in a large-diameter etching apparatus is to ensure uniformity. The most important and difficult parameter for determining this uniformity is the gas introduction method. There are various gas supply methods, such as 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, when the aperture ratio of the object to be etched greatly changes, the deposition properties of the center and the etch change, and it becomes difficult to obtain uniformity, especially in a large-diameter wafer.

The present invention has been made in order to solve the above problems, and has one or more processes or structures, for example, a contact structure in which the surface of the wafer is almost covered with resist and an etching area is half. The purpose is to etch both of the above wiring structures while ensuring uniformity. Another object is to achieve uniform etching of large diameter wafers. Further, the present invention allows the method of gas supply to be variable depending on the recipe, and widens the margin for adjustment of uniformity and the like.

[0005]

A semiconductor processing apparatus according to the present invention includes a processing tank, an upper electrode or an antenna, and a lower electrode, and a gas supplier for supplying a process gas into the processing tank. The semiconductor wafer is processed by generating plasma in the processing tank. This gas supplier accommodates a central distributor having a cylindrical shape and provided with rows of predetermined holes around the central distributor, and slidably accommodates the central distributor, and communicates with the outer surface from a position in contact with the central distributor. And a peripheral distributor having multiple gas paths formed therein. 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 made to communicate with each other according to the recipe, and the central distributor The process gas introduced into the processing tank is supplied from the outer circumference of the peripheral distributor into the processing tank. As a result, it becomes possible to perform uniform etching and the like on a large-diameter wafer.

According to another aspect of the semiconductor processing apparatus of the present invention, the central distributor defines a plurality of types of hole rows along the lengthwise direction corresponding to the recipe, and the central distributor corresponds to the recipe. Is rotated about the axis 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 semiconductor processing apparatus of the present invention, the central distributor defines a plurality of kinds of rows of holes along the circumferential direction corresponding to the recipe, and the central distributor corresponds 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 semiconductor processing apparatus of the present invention, the peripheral distributor defines a plurality of combinations of gas paths corresponding to the recipes, and the peripheral distributor distributes gas from the processing tank in accordance with the recipe. The distribution of the process gas supplied to the is controlled.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same or corresponding parts may be denoted by the same reference numerals, and the 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 also serving as a lower electrode installed in the lower part of the chamber, an upper electrode 13 arranged in the upper part of the chamber, and a lower part. And a control unit 14 arranged below the stage 12. Lower stage 1
A wafer 15 (semiconductor sample) is placed on the surface 2.
The control unit 14 includes a power introduction mechanism, an electrostatic chuck-related mechanism, 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 arranged below the upper electrode 13.

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

FIG. 2 is a diagram for explaining an example of the gas supply unit 20 in this embodiment. As shown in FIG. 2, the gas supplier 20 includes a central distributor 21 that is substantially cylindrical and located at the center, and a hemispherical peripheral distributor 22 that accommodates the central distributor 21 in the center. The central distributor 21 is provided with a large number of holes 21a provided on the cylindrical surface according to a predetermined rule. The peripheral distributor 22 is provided with a large number of gas passages 22a communicating from the position facing the holes 21a of the central distributor 21 to the outside. 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 and the selected group of holes 22a communicate with each other,
It is designed to conduct gas from the inside to the outside.

The process gas is supplied from the process gas supplier 20.
It is introduced into the central distributor 21 (central part) of the (gas supply kit) from the upper part of the chamber. The inside of the central distributor 21 is basically hollow although there are some ideas for reducing the volume. The central distributor 21 is a rotatable mechanism, and is shown by α in the figure.
Or the hole 2 of the type corresponding to the number of recipes, such as β
Row 2a is repeatedly opened.

Gas supply device (process gas supply kit) 2
It can be seen that many gas passages 22a are processed in the peripheral distributor 22 of 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 a row of four types of holes is repeatedly machined four times, the same cross section is found in the part rotated 90 degrees. Note that, as shown in FIG. 2, it is possible to widen the outlet at the end of the gas passage 22a of the peripheral distributor 22 to reduce the initial velocity of 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 and the gas path 22a of the peripheral distributor 22 communicate. There is. At 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 lowered a little, the hole 21a at the position of level x in the figure communicates with the gas passage 22a of the peripheral distributor 22 to introduce gas, and when it is moved up a little from the current position, the level y is reached.
Gas is introduced through the hole (path) at the position.

In the above example, it has been described that the central distributor 21 is provided with holes for determining two or more kinds of gas introduction paths, but the peripheral distributor 22 may be provided with two or more kinds of gas introduction paths. It is possible. That is, when you look at the cross section at a different angle, the path will change.

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

As described above, in this embodiment, the gas supply device (gas supply kit) is provided at the center of the upper electrode or the upper plate, and the gas supply device (gas supply kit) is used to make 2
The process gas is supplied to the chamber by the above method (flow direction and directivity). In order to realize a plurality of gas flow methods, a gas supplier (gas supply kit) is a hollow cylindrical central distributor 21 having a large number of holes and a peripheral distributor 22 having a large number of gas introduction paths. By rotating or vertically moving the central distributor 21 to a specified position according to the recipe, the gas is supplied from the portion where the hole 21a of the central distributor 21 and the gas path 22a of the peripheral distributor 22 are aligned with each other to the chamber. Release into.

Generally, there are many byproducts at the center of the wafer, and the depositability is stronger than that at the wafer edge, for example. The best way to reduce this effect is to blow a fresh process gas toward the center of the wafer, but this method can be achieved by using a recipe with many gas paths toward the wafer center. In other words, by supplying a gas with a flow rate above a certain level to the wafer center, the gas with a component with a strong depot property with a large proportion of biproduct is driven out and replaced with a fresh gas, and the gas with the wafer edge is replaced. The difference in the components of can be reduced. On the other hand, when the difference between the center and the edge is unlikely to occur and it is easier to obtain the uniformity by flowing the gas similarly to the center and the edge, 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 device (gas supply kit) is provided at the center of the upper plate of the processing device such as the etching device, and the ratio of the supply to the wafer center is increased to the edge. It has a mechanism that can change the flow rate of the gas, which has a higher ratio to that of the gas, or has a higher directivity (flow velocity) to a lower one. Process gas is a gas supply device (gas supply kit)
It is introduced from the back side of the upper plate to the central distributor (center portion) of the gas supplier. Many holes are opened in the center distributor (center part).
By rotating or moving up and down, the gas flows in conformity with the corresponding gas introduction path of the peripheral distributor. This rotation or vertical movement can be changed by the recipe. As a result, even if the etching pattern on the wafer surface is significantly different, it is possible to uniformly etch the entire surface of the wafer accordingly. Further, it becomes possible to perform uniform etching on a large diameter wafer.

[0021]

Since the present invention is constructed 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) It is possible to improve the uniformity of the etching shape in the wafer. (4) The macro loading effect can be reduced.

[Brief description of 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 for explaining a gas supply unit in this embodiment.

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

[Explanation of symbols]

10 Etching equipment 11 chambers (processing tanks) 12 Lower stage (lower electrode) 13 Upper electrode 14 Control unit 15 wafers (semiconductor sample) 20 Gas supply section (gas introduction section) 21 central distributor 21a hole 22 Peripheral distributor 22a gas path

Claims (4)

(57) [Claims] 1. A processing tank, an upper electrode or an antenna ,
In a semiconductor processing apparatus having a lower electrode and processing a semiconductor wafer by generating plasma in the processing tank, a central distributor provided with a row of predetermined holes in a cylindrical shape,
The central distributor is slidably accommodated around the center, and a peripheral distributor having a large number of gas paths leading to the outer surface from a position in contact with the central distributor is provided, and the central distributor and the peripheral distributor are provided. By changing the mutual positions of the central distributor, the row of holes of the central distributor and the gas path of the peripheral distributor are communicated with each other according to the recipe, and the process gas introduced into the central distributor is connected to the peripheral distributor. A semiconductor processing apparatus comprising a gas supplier for supplying the gas from the outer periphery into the processing tank. 2. The center distributor defines a plurality of rows of holes along the length direction corresponding to the recipe, and the center distributor is axially rotated according to the recipe to perform the center distribution. 2. The semiconductor processing apparatus according to claim 1, wherein a gas path of the peripheral distributor that communicates with the row of holes of the container is selected. 3. The center distributor defines a plurality of rows of holes along the circumferential direction corresponding to the recipe, and the center distributor is moved up and down according to the recipe to perform the center distribution. 2. The semiconductor processing apparatus according to claim 1, wherein a gas path of the peripheral distributor that communicates with the row of holes of the container is selected. 4. The peripheral distributor defines a plurality of combinations of gas paths corresponding to the recipe, and controls distribution of process gas supplied from the peripheral distributor into the processing tank according to the recipe. The semiconductor processing apparatus according to claim 1, wherein the semiconductor processing apparatus is configured to do so.