KR20040095088A - Electrode for a semiconductor device fabrication installation - Google Patents

Abstract

PURPOSE: An electrode for semiconductor fabrication process is provided to reduce the cost of consumable parts and troubles due to components, prevent reduction of efficiency of fabrication equipment, and enhance the productivity by improving a structure of the electrode. CONSTITUTION: An electrode for semiconductor fabrication process is formed with SiC. The electrode for semiconductor fabrication process further includes a plurality of gas distribution holes(12). The electrode is formed with a clamp type SiC electrode(10a). The gas distribution holes are formed on a planarized SiC plate.

Description

ELECTRODE FOR A SEMICONDUCTOR DEVICE FABRICATION INSTALLATION

The present invention relates to an upper electrode (also called an electrode) used in a semiconductor manufacturing process.

An electrode (cathode or UPPER ELECTRODE) is used to perform a dry etching process and a similar process used in a semiconductor manufacturing process. Generally, materials such as Si (silicon) or Al Anodized are used in current process conditions. However, in order to improve productivity and reduce costs of device manufacturers, DESIGN RULE is made smaller and the process conditions require high power, which is a critical condition.

As a result, the components of semiconductor facilities also have increased plasma, plasma, stress, fatigue, and the like, and the productivity-inhibiting factor of the components is increasing.

In general, the conventional electrode used for dry etching equipment is composed of high purity materials such as aluminum, quartz (QUARTZ), and silicon (SILICON), etc., which are fixed to the chamber by various fastening methods and clamp methods. It is dLT is configured to be used as an electrode to uniformly supply the reaction gas and form a plasma.

Representative silicon electrodes (silicon cathode) used in the prior art generally have a simple single crystal structure and exhibit a fairly stable phenomenon in terms of particles during the process. As the device is highly integrated, the RF power applied to the equipment is rapidly increased, thereby increasing the thermal stress on the Si electrode, and the damage of the paste is also increased as the etching by plasma and process gas increases. It became. As a result, the device manufacturer's facility utilization rate is also lowered due to component failures and shorter replacement cycles, resulting in cost improvement and lower productivity.

In addition, crack and broken phenomena are also generated at the joints, assemblies, fasteners, and SHARP EDGE due to the thermal effects of the current parts. This phenomenon is a factor that increases the overall cost of equipment maintenance and manufacturing.

Similarly, in the case of the Al ENODGE electrode, the Al 2 O 3 surface, which is an anodizing surface, is etched, causing a problem of Al component contamination along with a process problem such as ARCING. The problem with these components is a cost increase for semiconductor manufacturers.

The present invention is to solve such a conventional problem, the purpose of which is to reduce the cost of parts (COST OF CONSUMABLE PARTS) caused by regular replacement when using the current materials and the existing products It is to provide an electrode used in a new type of semiconductor manufacturing process that can increase the productivity per unit time by improving the efficiency of the PLASMA integrated state by preventing the occurrence of abnormalities due to components, reduction of equipment efficiency.

1 shows a clamped SiC electrode according to the invention;

2 is a view showing a screw fixing electrode;

3 shows a screw-shielded (SCREW-SHIELDED) type electrode;

4 is a view showing an electrode of a support ring type (SUPPORT RING TYPE);

5 shows a backside screw type electrode 10e;

FIG. 6 is a graph showing polymer depot characteristics of the backside of the SiC electrode of the present invention and the conventional Si electrode.

* Description of the symbols for the main parts of the drawings *

10a: SiC electrode

The present invention for achieving the above object is characterized in that the upper electrode used for the dry etching process and the process corresponding thereto is made of a SiC material.

Compared with the existing materials, SiC electric poles have high corrosion resistance and high strength properties, which can reduce the cost by improving the service life by several times. SiC is etched slower than other materials and also has a high durability and structural advantages.

In addition, the characteristics of the SiC electrode may solve various component problems that occur during the installation of the equipment and the process. For example, in the case of a silicon electrode that is commercially available and used, cracks may be generated from edges or notches during etching, and parts may be broken, and thermal deformation The same phenomenon may occur. In addition, silicon is unstable in the manufacturing process and characteristics of its parts, and thus it is very limited in manufacturing shape, thus maintaining other materials and assembling shapes-for example, LAM's ELASTOMER BONDED SILICON CATHODE- As a bonding method, bonding is performed by using a binder such as metal (METAL) or polymer (POLYMER), and this bonding layer (LAYER) generates DE-BONDING (separation state of silicon and other materials) during the process. It is also a cause for reducing the efficiency of the installation. However, by using the SiC material, this can be solved by making only the SiC itself material, not the assembly state during the shape sintering. This point is also reduced due to the deformation of the part or the stress due to the smaller thermal gradient of the part. There is an advantage that can greatly improve the destruction.

Lastly, unlike aluminum and silicon, SiC is easy to control the electrical properties, and the thermal conductivity is also excellent, which limits the plasma during the process. The superiority of the SiC material means that the thermal resistance generated during the process is small, which can increase the plasma density generated between the two electrodes to which RF is applied, and alternating to other parts of the chamber (WALL, LINER, RING, etc.). In effect, the plasma pattern is also very good. This can be checked in the PARAMETER, such as RF REFLECT ERROR. Due to these factors, when the SiC electrode is used, its productivity may be increased in preparation for other materials.

As described above, the SiC electrode may bring various excellent effects, and there is an advantage in that the performance of the SiC electrode may be variously changed according to the manufacturing method of the SiC.

For example, the embodiments of the present invention may be modified in various forms, and the scope of the present invention should not be construed as being limited by the embodiments described below. These examples are provided to more fully explain the present invention to those skilled in the art. Accordingly, the shape of the elements in the drawings and the like are exaggerated to emphasize a clearer description.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings, FIGS. 1 to 6. In the drawings, the same reference numerals are given to components that perform the same function.

As described above, the SiC electrode of the present invention is characterized as follows. SiC electrode can be improved physical properties compared to the typical representative material Si. It has excellent properties in strength, hardness, etc. to determine the structural part of the physical properties, and may be changed or improved depending on the use and manufacturing cost. In addition, most of the thermal and electrical characteristics that have a great effect on the process are also largely different from existing materials and can be replaced. These parts can be changed in consideration of the design of the product.

Representative characteristics in the table below are compared with SILICON materials.

Table 1. Comparison of Characteristics of Typical Si and SiC>

The above table is a characteristic value of typical SiC products, and the physical properties may be changed by adjusting the manufacturing process or its composition.

The structure of the SiC electrode of the present invention can have a variety of structures according to the features of the facility as shown below.

Referring to FIG. 1, the clamp type SiC electrode 10a is composed of a plurality of gas distribution holes 12 in consideration of the wafer size from the center of the hole HOLE in a flattened SiC plate. have. There is a little space on the outside for mounting this electrode in the facility and vacuum sealing, and it is mounted by clamping it with other parts with sufficient structural durability.

This design is subject to bending stress throughout the circumference and thermal deformation (EXPANSION, DISPLACEMENT). By developing this phenomenon with SiC, tens of percent of improvement is possible.

Referring to FIG. 2, the screw fixing electrode 10b is an improvement of the clamping type of FIG. 1. The material is also made of SiC and its design consists of a plurality of gas distribution holes 12 in consideration of the wafer size from the center of the hole on the flattened SiC plate, and screwed for assembly in the outer space for assembly mounting. The part 14 is designed in several places. The screw fastening portion 14 may be manufactured by counterboring, countersinking, tapping, or the like. Considering the durability and sealing characteristics of the material, it is necessary to determine an appropriate fastening method. The screw method can prevent the leakage (LEAK) due to deformation during the process.

Referring to FIG. 3, a screw-shielded electrode 10c is an improvement of the screw method. The material is also made of SiC and the design of the flattened SiC plate consists of a plurality of gas distribution holes 12 in consideration of the wafer size from the center of the hole, and screw fastening for assembly in the outer space for assembly mounting (14) is designed in several places and reinforced ring-shaped shielding function to suppress arcing, particle generation, and plasma confinement fluctuation due to exposure of screw part. Considering the durability, sealing and confining properties of the material, an appropriate edge area shielding area may be determined.

The electrode 10d of the support ring type of FIG. 4 is designed to expand an area actually used as an electrode among various structures and to improve an assembly method. The material of the electrode part is also made of SiC, and its design is composed of a plurality of gas distribution holes 12 in consideration of the wafer size from the hole center on the flattened SiC plate. The ring 16 is in contact with the electrode. The supporter ring 16 is made of the same material when the SiC electrode is manufactured, and has an integral structure as shown in the right side of the cross section at the bottom of the drawing through heat treatment or the like. Of course, it is possible to have a structure in the assembled state by a fastening method or a joining method by being manufactured separately by the same material or other materials as the right side of the bottom. The supporter ring 16 can be used for mounting in a chamber by various methods such as a clamp ring or a screw.

As shown in FIG. 5, the electrode 10e of the backside screw type may be used when the chamber structure is slightly different. Some installations have buffering components on the electrodes to enhance gas distribution, making it impossible to assemble them from the back, but some installations may mount the electrodes directly to the chamber. In this case, the electrode is designed to be fastened on the opposite side of the chamber. Also, the material is made of SiC, and if the processability of SiC is difficult, the screw fastening part may be manufactured by using a HELICOIL. In the drawing, the exposed portion of the electrode portion has a slope (SLOPE) is designed to enhance the plasma confinement and increase the area. In the case of fastening and mounting directly on the back, no other parts are required to mount the electrode, and a simple chamber design is possible.

As described above, the SiC electrode may be designed and used in accordance with the structure and process characteristics of the equipment used and the manufacturing process of the component. In general, the structure of the electrode is designed through the determination of the material, the structure of the chamber, the assembly method, and the plasma confinement function. In the case of SiC electrode, if the number of holes and the assembly method are determined, it is optimized and manufactured through various processing processes. Of course, the cost of the wafer manufacturer must be considered.

As emphasized in the object and features of the invention above, the features of the SiC electrode invention are as follows.

First, it shows the biggest characteristic of its service life.

Representatively, the same equipment and the same process as Si were compared. Table 2 below shows the weight of the electrode etched by the same 50Hr process.

In the first five 50Hr steps below, the etching weight was measured by the AGING condition (Si DUMMY WAFER) while the plasma of the existing Si electrode and the SiC electrode were turned on, and the last 50Hr was RUN WAFER as the actual process condition. This is the result. As can be seen from the results, the etching amount of the SiC electrode at the same time is about 1/5 of AGing condition compared to Si, and about 1/2 in RUN condition. The difference between these conditions is that the wafer has a change in the etching amount of the electrode depending on the film quality exposed, and on average, SiC has a 2-3 times higher plasma or corrosion resistance than Si. can do.

<Table 2. Etch Amount of Si and SiC Electrode (Weight, g)>

Comparing only the etching amount according to the use time in Table 2, it can be seen that the use life of SiC is significantly greater. In addition, SiC electrodes have considerably high characteristics not only in hardness and strength but also in flexural strength. This means that the lifespan until disposal of the electrode is improved. In practice, in the case of LAM's RAINBOW facility, cracks and brokines of parts are generated during the process when the thickness of the existing Si electrode is about 4mm, but SiC is about 2mm left (this is about 5 Pear life). In many respects, SiC can improve the life expectancy by more than three times in consideration of process characteristics and facility characteristics.

The second feature is its capability improvement.

In the case of SiC electrodes, the difference between the electrical and thermal characteristics of the SiC electrode causes a difference in impedance between the electrodes of the installation, which is accompanied by a change in plasma density. Due to this difference, the use of SiC electrode shows an excellent improvement in the etching rate and selectivity. In particular, depending on the film quality of the wafer, the difference from the insignificant to the significant difference. Representative below is a process change in using Si and SiC electrodes of the PAD ETCH process.

<Table 3. Process Capability with Si and SiC Electrodes>

As shown in Table 3 above, it can be seen that the etching rate is improved by about 10% in the process of mainly etching the BPSG film like the PAD process. This improvement in etch rate and selectivity also directly increases the productivity of the plant. The process conditions of the same process tested in Table 3 above are shown below.

<Table 4. Process conditions and S / T of Si and SiC electrodes

As shown in Table 4, the representative devices that are manufactured and produced are shown to show that the improvement of the etch rate leads to the reduction of the etching time, which can improve the productivity of the facility. In the table above, the standard time has been reduced by about 10%, and in facilities such as multi-chambers, the uptime can be further improved.

The third is the change in the etch state of the parts and the characteristics of the POLYMER DEPO.

Each electrode photograph was compared in FIG.

As shown in FIG. 6, the SiC and Si electrodes exhibit enormous differences in the polymer depot properties of the backside. In the case of conventional Si, polymer depots are heavily made around the centers and centers that appear to be arcing. Such a polymer is introduced into the chamber space during the distribution of the reaction gas, or falls on the ESC, causing wafer leakage. This leads to inefficient loss (LOSS), such as reduced facility utilization, increased facility PM time, and increased cleaning costs for parts.

However, in case of SiC, even if the use time is increased, there is almost no increase in hole size due to hole etching, and there is no phenomenon of lower hole widening like funnel. none. On the contrary, in the case of using SiC electrodes, the regular use time is increased, thereby improving the operation rate, extending the PM cycle, and reducing the cleaning cost.

In summary, the effects of the present invention can be summarized as follows: 1) extending the service life by reducing the etching amount of the electrode base material; Can be summarized.

The present invention can be applied to a component that functions as an upper electrode (cathode) or a general showerhead (gas distribution) used in a facility that performs a dry etching process in a semiconductor manufacturing process. In addition, it can be applied to the parts of the process equipment that functions the same as the showerheads of the CVD equipment. In the case of SiC-developed products, the workability is difficult compared to parts such as aluminum.

In such a case, as mentioned in the structure of the invention above, it is possible to manufacture a part, etc., in which the same base material is integrally formed through a process according to heat treatment by changing the fastening method or separately manufacturing the SiC material. Of course, in unusual cases, only the plate part and other functional supporter rings or fastening element parts of the electrode components may be manufactured using other materials, and then the finished product may be configured using banding or fastening elements. As mentioned in the development purpose, in order to solve the etching, generation of pollutants, and the increase of cost caused by the existing materials, the adoption of SiC is possible to apply optimized SiC electrodes through various structural designs. will be.

The practical application of the present invention is preferably developed and applied to LOX's OXIDE process equipment-in particular, EXELAN equipment and RAINBOW equipment using Si electrodes-in the semiconductor manufacturing process, and TEL's SCCM MODEL. It is also applicable to electrodes of OXIDE process equipment such as equipment. It can be applied to many other process facilities, and the same characteristics can be maintained in parts such as shower heads of CVD.

SiC materials can be applied to high-purity SiC such as SINTERED SiC, re-reacted SiC, and reacted sintered products according to their characteristics. However, the material may be optimized and selected in accordance with the purpose of the invention.

In the above, the configuration and operation of the electrode according to the present invention is shown in accordance with the above description and drawings, but this is only an example and various changes and modifications are possible without departing from the spirit of the present invention. .

In summary, the effects of the present invention can be summarized by extending the service life by reducing the amount of etching of the electrode base material, improving the process capacity such as ETCH RATE, selectivity, increasing the operation rate and cost by reducing the LOSS due to parts.

Claims (2)

In an electrode supplying power for plasma generation in a semiconductor manufacturing process: The electrode is used in a semiconductor manufacturing process, characterized in that the SiC material. The method of claim 1, The electrode is An electrode for use in a semiconductor manufacturing process characterized by having a plurality of gas distribution holes for reactive gas distribution.