KR20010006881A - Apparatus and method for processing semiconductor piece - Google Patents

Abstract

PURPOSE: To contrive to enhance uniformity in a contact structure and a wiring structure by a method wherein a gas supply port is positioned at an intermediate position between an upper electrode and a lower electrode to supply a gas for plasma. CONSTITUTION: A power is introduced from an upper electrode 13 or an antenna into the interior of a chamber 10 to discharge, thereby producing plasma. A wafer 15 mounted on a lower stage 11 is etched with a plasma gas. A gas supply part 12 is structured by a radial pipe disposed radially from the center as an axis, annular pipe, and a vertical pipe serving also as a supporter. A plurality of pipes are interconnected so as to introduce the plasma gas. It is possible to adjust arbitrarily the number and placement of the radial pipe, the annular pipe, or the vertical pipe. An interval of the neighboring vertical pipe is set to be a wafer diameter or more so as to insert the wafer 15. The wafer 15 is mounted just under the gas supply part by a conveyance robot.

Description

Processing device and processing method for a semiconductor sample {APPARATUS AND METHOD FOR PROCESSING SEMICONDUCTOR PIECE}

TECHNICAL FIELD This invention relates to the processing apparatus and processing method of the semiconductor sample which performs the process using a plasma, and especially relates to the etching apparatus or ashing apparatus, such as a semiconductor wafer, and its method.

The most important and difficult thing in an etching apparatus is ensuring the uniformity of etching. What is important in determining this uniformity is to make each parameter of plasma, gas flow, pressure, etc. uniform on the wafer. In particular, such as the development of a 300 mm-compatible etching apparatus, it is a method of uniformly supplying gas that is difficult with a large-diameter etching apparatus.

In the etching apparatus, in order to make the flow of gas uniform, the exhaust of the gas must be made uniform. However, even if the gas is supplied symmetrically from the wafer periphery, the gas supply position is far from the wafer. At the edges, the flow or composition of gas tends to be uneven.

In the case of using a shower head, it is possible to arrange | position on the upper side of a wafer, and it is used as a method which can supply a gas uniformly.

However, if the shower head approaches the wafer too much, it becomes difficult to ensure the uniformity of pressure and leads to deterioration of the uniformity of etching characteristics.

Particularly in the case of large diameter cure, this problem is serious. For example, an etching apparatus of 300 mm is manufactured with a gap equal to 200 mm (the distance between the upper and lower electrodes or the wafer and the shower head) using a parallel plate type etching apparatus. In this case, a pressure difference occurs between the center portion and the edge portion of the wafer, and it is difficult to obtain uniformity of etching.

In addition, when the gap is widened, the advantage of supplying gas directly above the wafer becomes slim.

Subsequently, it is important to ensure uniformity of etching and to secure a wide process window. In particular, when one device is used to etch another kind of structure such as contact hole, wiring or groove processing, it becomes a problem.

This is likely to cause a difference in etching characteristics between the wafer center portion with a lot of by-products (etched products) supplied from the wafer and the wafer edge portion with less objects to be etched around, and this can be corrected by a gas supply method. When the structure of the etching target is changed, it is very difficult to realize the uniformity at the center and the edge in one or more processes.

The present invention has been made to solve the conventional problems as described above, and the present invention makes it possible to widen the gap in order to secure the uniformity of pressure in the processing tank, while supplying the gas is directly above the wafer. It aims at ensuring the uniform process also in the etching apparatus corresponding to large diameter.

In addition, an object of the present invention is to ensure uniformity and etching of both a contact structure in which at least one process, for example, the surface of a wafer is substantially covered with a resist, and a wiring structure having an etching area of at least half. .

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

FIG. 2 is a perspective view for explaining a specific structure of the gas supply unit in FIG. 1; FIG.

FIG. 3 is a partially enlarged view of the radial tube or annular tube of the gas supply unit seen from the wafer side in FIG. 2; FIG.

4 is a cross-sectional view showing a schematic structure of an etching apparatus according to another embodiment of the present invention.

<Description of the code | symbol about the principal part of drawing>

10: chamber (treatment tank)

11: lower stage (lower electrode)

12 gas supply unit

13: upper electrode

14: control unit

15 wafer (semiconductor sample)

11: radial coronation

22: annular hall

23: vertical tube

24: hole (gas supply port)

In order to realize this, the processing apparatus for a semiconductor sample of the present invention includes an upper electrode and a lower electrode in a processing tank, and generates a plasma between the two electrodes to process the semiconductor sample. And a gas supply means for supplying a gas for plasma by placing a gas supply port at an intermediate position of the lower electrode.

In addition, another semiconductor sample processing apparatus of the present invention includes an upper electrode and a lower electrode in a processing tank, and generates a plasma between the two electrodes to process a semiconductor sample. In addition to the gas introducing means for introducing the gas for the plasma in the gas supply means for supplying the gas for plasma by placing a gas supply port in the intermediate position between the upper electrode and the lower electrode.

Moreover, the processing apparatus of the other semiconductor sample of this invention is characterized in that the said gas supply means distribute | circulates the gas for plasma inside, and is comprised combining the several pipe | tube which has many gas supply ports.

Moreover, the processing apparatus of the other semiconductor sample of this invention is characterized by the said gas supply means provided with the control means which variably controls the distance of the said gas supply port and the said semiconductor sample.

Moreover, the processing apparatus of the other semiconductor sample of this invention is characterized in that the said gas supply means has many gas supply ports with distribution adjusted according to the surface of the said semiconductor sample.

Moreover, the processing method of the semiconductor sample of this invention is characterized by processing a semiconductor sample by supplying plasma gas to the intermediate position of the upper electrode and lower electrode in a processing tank.

In addition, according to another method of processing a semiconductor sample of the present invention, the plasma sample is supplied from the upper portion or the side portion of the treatment vessel, and the plasma sample is supplied to the intermediate position between the upper electrode and the lower electrode in the treatment vessel. It is characterized by processing.

In another method of processing a semiconductor sample of the present invention, the plasma gas to be introduced into the upper or side portion of the processing tank and the plasma gas to be supplied to an intermediate position between the upper electrode and the lower electrode may be different gases. do.

Embodiment 1

1 is a cross-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 includes a chamber 10 (treatment tank), a lower stage 11 serving as a lower electrode provided below the chamber, and a gas supply port so as to be movable up and down in the chamber. The provided gas supply part 12 and the upper electrode 13 arrange | positioned at the upper part of a chamber. On the lower stage, a wafer 15 (semiconductor sample) is placed.

In addition, the control unit 14 is disposed below the lower stage 11. The control unit 14 includes a mechanism for moving the gas introduction unit 12 up and down, and includes a power introduction mechanism, an electrostatic chuck relationship, a wafer lift mechanism, a wafer temperature control mechanism, and the like.

In the chamber 10, discharge is generated by the introduction of power from the upper electrode 13 or the antenna, and plasma is generated. The wafer 15 loaded on the lower stage 11 is etched by this plasma gas.

FIG. 2 is a perspective view for explaining a specific structure of the gas introducing unit 12 in FIG.

The gas supply part 12 is comprised from the radial tube 21 arrange | positioned radially from the center, and becomes a shaft, the ring-shaped annular tube 22, and the vertical tube 23 which serves as a support, and these several tubes are for plasmas. It communicates so as to conduct gas.

The number and arrangement of the radial tube 21, the annular tube 22, and the vertical tube 23 can be arbitrarily adjusted. However, the space | interval of the adjacent vertical pipe 23 shall be more than the wafer diameter so that the wafer 15 can be inserted. The wafer 15 is loaded directly under the gas supply unit 15 by the transfer robot.

The vertical pipe 23 is connected to the actuator of the control part 14, and can move up and down as a recipe.

The radial tube 21, the annular tube 22, and the vertical tube 23 are hollow pipes, and process gas flows through them. The gas is introduced into one or more vertical pipes 23, and the gas is also discharged into one or more vertical pipes 23.

3 is a partially enlarged view of the radial tube 21 or the annular tube 22 viewed from the wafer side. As shown in the figure, a gas blowing hole 24 (gas supply port) is opened on the wafer side of these pipes. The number (density) of the holes 24 can be arbitrarily adjusted, and can be changed to the center portion and the edge portion in order to improve the uniformity of etching on the wafer surface. Also, the size of the hole 24 can be changed to the center and the edge. In addition, the direction of the hole 24 can also be opened in the downward inclined direction, the horizontal direction, or the upper direction (on the opposite side of the wafer and in the upper electrode direction) in addition to just below.

Next, this etching apparatus demonstrates a specific structure and the form of use. As an example, the example of the parallel plate type (300-mm wafer-compatible oxide film etching apparatus) which can apply the power of a different frequency to an up-and-down electrode is mentioned, for example.

An example of etching conditions is as follows.

Pressure: 40mTorr,

Gas flow rate: C4F8 = 50sccm, Ar = 300sccm, CO = 200sccm, 02 = 30sccm

Power: Top electrode 3000 W (13.56 MHz), Bottom electrode 1000 W (400 kHz)

It is possible to ground the lower part and to apply magnetic field

Gap: 10 cm

Gas supply height: variable from several millimeters to 10 cm

In the case of etching under the above conditions, since the gap is sufficiently wide, the pressure uniformity is not a problem, and the distance from the plasma of the high electron temperature to the wafer is far from the electrode, and there is no worry of damage or electron shading.

When the etching target is to be etched at a high rate or under conditions in which ions (charged particles) are increased with respect to neutrals such as radicals, the gas supply part is set to the highest or the position of the upper electrode. In this case, it becomes a condition close to the etching in the conventional shower head.

On the other hand, when (a) it is desired to improve the nonuniformity between the center and the edge, such as to improve the adhesion of the adhesive at the center too much or to reduce the decrease in the selection ratio at the edge, or (b) the dissociation does not proceed more. In order to improve the selection ratio of resist to resist, SiN, and Si by etching with gas, the height of the gas supply part is set to 10 mm, for example.

As described above, the gas supply part 12 is made of a plasma-resistant material such as quartz (Quartz) immediately above the wafer 15, and is configured as a shower head type that does not shield plasma.

Since this gas supply part 12 is not a flat plate but consists of a pipe which passes gas, it can be placed in a plasma, and since many holes are open in a pipe, it is possible to supply gas uniformly to a wafer. .

In addition, since the gas supply part 12 can move up and down by a recipe, and even if the structure to be etched changes, the gas supply part 12 can be set to an optimal height with a recipe, Even etching is possible.

Next, the operation and action of this etching apparatus will be further described.

In general, there are many by-products in the center of the wafer, for example, the adhesion is stronger than the wafer edge portion. In order to reduce this effect, it is a suitable method to supply fresh gas from the vicinity of the wafer, but it is realized by using this structure.

That is, a gas having a certain flow rate or more is supplied to the wafer center from the vicinity of the wafer to expel a gas having a strong adhesion component with a large proportion of by-products, and replace it with a fresh gas, and replace the gas with the wafer edge. The difference can be reduced.

Depending on the structure of the etching target, when the action is to be strengthened, the gas supply unit may be close to the wafer by the recipe.

The height of the gas supply part greatly affects the degree of dissociation of the gas. That is, the gas is decomposed to lower molecules, radicals, and ions in the plasma until the ejected gas reaches the wafer, but the decomposition degree is small when the distance from the wafer is close. In view of this, an optimal height is set for each structure.

As described above, according to this embodiment, since the present invention ensures the uniformity of the pressure in the chamber, it is possible to widen the gap while supplying the gas directly above the wafer by the gas supply part. Therefore, even in the etching apparatus corresponding to large diameter, a uniform process can be ensured.

Further, according to this embodiment, one or more processes, for example, the contact structure of which the surface of the wafer is almost covered with the resist and the wiring structure of which the etching area is half or more can be etched while ensuring uniformity. have.

Embodiment 2

4 is a cross-sectional view showing a schematic structure of an etching apparatus according to another embodiment of the present invention.

This embodiment adds the gas supply part 12 and control mechanism which were demonstrated by Embodiment 1 to the conventional etching apparatus which supplies gas from the upper part and the side wall of the chamber 10. As shown in FIG. Reference numerals in the drawings show the same as those in Figs. 1 to 3, and thus detailed description thereof will be omitted.

In this etching apparatus, as shown by the reference numeral g, the gas is supplied from the upper side or the sidewall of the chamber 10 as conventionally. Moreover, as shown by the h, the gas is supplied from the gas supply port 23 of the gas supply part 12 which leads to an actuator and which can move up and down by a recipe.

By supplying the gas into the chamber 10 in two ways as described above, the possibility of controlling the supply amount of the gas, its distribution, and the gas velocity can be further increased.

In this case, it is also possible to change the kind of gas by the gas flow g and the gas flow h.

For example, among total gas flow rate: C4F8 = 50sccm, Ar = 300sccm, CO = 200sccm, 02 = 30sccm, C4F8, which does not want to dissociate very much, flows into the plasma as a gas flow h, and other gas is It is also possible to flow from the upper part of the chamber 10 as a flow g.

In addition, for example, the material related to etching is supplied from the gas supply port 23 of the gas supply part 12 in order to, for example, raise the selectivity from the plasma immediately above the wafer 15. This is the case of using S1C, S1, SiN, C as the consumption material of the entire gas supply part or the wafer surface part.

As mentioned above, also in this embodiment, it is set as the structure which can flow gas to several concentric rings and several pipes which connect these, and provides the hole which blows gas to a wafer rather than the many hole opened in the pipe. .

This makes it possible to supply the gas for plasma in the plasma generation region near the wafer, i.e., to keep the gas supply portion close to the wafer while maintaining the upper plate which determines the plasma space.

In addition, the height of this gas introduction can be made variable by a recipe, and the margin of uniformity adjustment etc. becomes wider. In addition, the gas can be supplied from a large number of holes in a wide area as in the conventional shower head, and since the gas is in the vicinity of the wafer, the amount of gas is optimized to the center and the edge of the wafer by adjusting the number of holes. It is easy to make it. This enables uniform etching of large diameter wafers. As for the material, quartz (Quartz) is suitable, but by using this as C, Si, SiC, it is also possible to give a scarr effect such as F directly above the wafer.

Also in this embodiment described above, of course, the same effect as that of the first embodiment is obtained.

As described above, according to the etching apparatus of the present invention, the following effects are obtained.

(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 etching shape in the wafer can be improved.

(4) The micro loading effect can be reduced.

(5) Improved selection ratio of resist and resist.

(6) The charge up damage can be reduced.

Claims (8)

A processing apparatus including 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 the gas supply port supplies a gas for plasma to an intermediate position between the upper electrode and the lower electrode. An apparatus for processing a semiconductor sample, comprising: a gas supply means having a gas; A 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, comprising: gas introduction means for introducing a gas for plasma from the upper side or the side of the processing tank And a gas supply means having a gas supply port for supplying a gas for plasma to an intermediate position between the upper electrode and the lower electrode. The semiconductor sample processing apparatus according to claim 1 or 2, wherein the gas supply means is configured by distributing a gas for plasma therein and combining a plurality of tubes having a plurality of gas supply ports. ． The semiconductor sample processing apparatus according to claim 1 or 2, wherein the gas supply means includes control means for controlling the distance between the gas supply port and the semiconductor sample to be variable. The semiconductor sample processing apparatus according to claim 1 or 2, wherein the gas supply means includes a plurality of gas supply ports whose distribution is adjusted in correspondence to the surface of the semiconductor sample. A method for processing a semiconductor sample, comprising supplying a plasma gas to an intermediate position between an upper electrode and a lower electrode in the processing tank and processing the semiconductor sample. A method for processing a semiconductor sample, comprising introducing a plasma gas from an upper portion or a side portion of a treatment tank and supplying a plasma gas to an intermediate position between an upper electrode and a lower electrode in the treatment tank. The plasma sample processing method introduced into the upper or side part of the said processing tank, and the plasma gas supplied to the intermediate position of the said upper electrode and a lower electrode are made into another gas, The semiconductor sample processing method characterized by the above-mentioned.