KR20110078256A - Pusher of a chemical-mechanical polishing apparatus - Google Patents

Abstract

PURPOSE: A pusher of a chemical-mechanical polishing apparatus is provided to increase the yield of a wafer by preventing a wafer pusher from becoming damaged because of the wafer being wrongly mounted in a pusher due to the surface tension between the two. CONSTITUTION: In a pusher of a chemical-mechanical polishing apparatus, a liquid nozzle(110) and a gas injection nozzle(120) are formed around a pusher(100) alternately. The liquid nozzle is connected to a deionized water / liquid supply line(113) and discharges the deionized water / liquid. The deionized water / liquid supply line supply is connected to a hydrophilic deionized water supply unit(111) and a hydrophobic liquid supply unit(112). The gas injection nozzle is connected to a nitrogen supply line(122). The gas injection nozzle discharges nitrogen gas by controlling the valve of the nitrogen gas supply unit.

Description

Pusher of a chemical-mechanical polishing apparatus

The present invention relates to a pusher of a chemical mechanical polishing apparatus, and more particularly, when a wafer is dropped onto the pusher by injecting gas and liquid from the pusher when transferring the wafer from the CMP head holding the wafer to the pusher by vacuum adsorption of the wafer. A pusher of a chemical mechanical polishing apparatus capable of reducing the physical impact of a wafer.

The reduction in device size due to the increase in the degree of integration of semiconductor devices and the multi-layer interconnect process required for the implementation of complex functional integrated circuits have become more practical, and the importance of global planarization in interlayer dielectrics (ILD) is added. I'm going.

The planarization process is largely a method of etching back the surface of the wafer to a certain thickness, a reflow method of achieving flattening by melting the surface at a high temperature, and scrubbing the surface of the wafer using an abrasive. Chemical-mechanical polishing (hereinafter referred to as "CMP") method.

Recently, a chemical mechanical polishing process is widely used during the planarization process. The chemical mechanical polishing process is a chemical removal process and a mechanical removal process, in which a surface of a wafer having a step is closely adhered to a polishing pad. A slurry containing a material is injected between the wafer and the polishing pad to planarize the surface of the wafer.

Conventional chemical mechanical polishing apparatus includes a polishing platen in which the surface of the wafer is adhered and polished, a CMP head mounted on the polishing platen and polished by vacuum suction and rotation of the wafer, and loading / loading from the CMP head. And a pusher on which the unloaded wafer is seated, and a rotary transporter for loading / unloading the wafer into the pusher.

Referring to the wafer transfer process of the conventional chemical mechanical polishing apparatus having such a structure as follows. First, when the CMP head moves the polished wafer to the pusher insertion hole of the rotary transporter, the wafer is inserted into the pusher insertion hole by spraying nitrogen (N2) and ultrapure water through the nitrogen and ultrapure water injection holes provided on the lower side of the CMP head. The wafer is transferred.

However, such a conventional chemical mechanical polishing apparatus has a surface tension between the bottom of the CMP head and the wafer due to ultrapure water when the CMP head puts the wafer on the pusher, so that the wafer is not completely separated from the CMP head. In the wafer, the wafer is incorrectly seated in the pusher and is broken or subject to physical shock. Therefore, there is a problem that the yield of the wafer is significantly reduced as well as the operation of the apparatus due to the breakage of the wafer.

The present invention has been made to solve the above problems, when the wafer is vacuum-adsorbed to the pusher when the wafer is transferred from the CMP head holding the wafer to the pusher by spraying the gas and liquid in the pusher when the wafer falls on the pusher It is an object of the present invention to provide a pusher of a chemical mechanical polishing apparatus which can reduce the physical impacts received.

The pusher of the chemical mechanical polishing apparatus of the present invention for achieving the above object is a pusher of the chemical mechanical polishing apparatus in which the wafer is separated from the CMP head and seated to transfer the wafer which has been polished in the chemical mechanical polishing process to the next process. In the case, the wafer is separated from the CMP head to the pusher characterized in that the liquid injection port and the gas injection port is formed alternately formed at regular intervals around the edge of the pusher to reduce the physical impact.

In addition, the liquid injection port is connected to the ultra pure water supply line of the hydrophilic ultra pure water (DI) water supply unit and the liquid supply line of the hydrophobic liquid supply unit, and sprays the hydrophobic liquid when the wafer is hydrophilic, and hydrophilic when the wafer is hydrophobic It is characterized by spraying ultrapure water (DI) water.

In addition, the gas injection port is connected to the nitrogen supply line of the nitrogen gas supply is characterized in that for injecting nitrogen gas.

According to the pusher of the chemical mechanical polishing apparatus according to the present invention, the CMP head absorbs the wafer and injects gas and liquid from the pusher when transporting the pusher to reduce the physical impact the wafer receives when the wafer falls on the pusher, The surface tension between the generated wafers prevents the wafer from being accidentally seated on the pusher and is damaged, thereby improving the operation rate of the equipment and increasing the yield of the wafer.

Hereinafter, the configuration and operation of the preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. Here, the same reference numerals will be used for the same components as the prior art.

1 is a block diagram showing a pusher of the chemical mechanical polishing apparatus according to the present invention.

As shown in FIG. 1, the pusher of the chemical mechanical polishing apparatus of the present invention is configured to reduce the physical impact when the wafer 10 is separated from the CMP head 20 and falls into the pusher 100. It consists of a liquid injection port 110 and a gas injection port 120 are formed alternately around the edge of the. In other words, when the wafer falls on the pusher 100, the gas and liquid are properly injected from the pusher 100, thereby reducing the physical impact on the wafer.

2 is a cross-sectional view of the pusher of the chemical mechanical polishing apparatus according to the present invention.

As shown in FIG. 2A, the pusher 100 has a liquid injection port 110 and a gas injection port 120 that are alternately formed at regular intervals around an edge circle of the pusher 100, and FIG. 2B is a cross section of each injection hole. When the wafer falls to the pusher 100 serves to reduce the falling speed of the wafer by spraying liquid and gas from the liquid injection port 110 and the gas injection port 120 located at the edge of the wafer.

Figure 3 is a schematic diagram showing a process of seating a wafer on the pusher of the chemical mechanical polishing apparatus according to the present invention.

3A shows that the wafer 10, which has been polished by chemical mechanical polishing, is positioned above the pusher 100 to be vacuum-adsorbed to the CMP head 20 to transfer the wafer to the pusher 100. FIG. 3B illustrates liquid and gas in the liquid injection hole 110 and the gas injection hole 120 when the wafer is separated from the CMP head 20 by the air injection hole provided on the lower side of the CMP head 20 and falls on the pusher 100. Show that you are spraying.

In the case where the wafer 10 vacuum-adsorbed to the CMP head 20 is hydrophilic, the liquid jet sphere 110 may use a hydrophobic liquid (for example, tetramethyammonium hydroxide) opposite to the hydrophilic wafer. Spray. On the other hand, when the wafer is hydrophobic, the liquid injection port 110 injects a hydrophilic liquid (for example, ultra pure water: DI water) opposite to the hydrophobic wafer. In other words, by injecting a liquid having a different property from the wafer, when the wafer falls on the pusher, the wafer is pushed out to act as a buffer.

At the same time as the liquid is injected, nitrogen gas is continuously injected at a predetermined pressure in the gas injection port 120 to reduce the physical impact that may occur on the wafer when the wafer 10 falls on the pusher 100.

The liquid injection port 110 is connected to an ultrapure water / liquid supply line 113 for supplying a hydrophilic ultrapure water supply unit 111 and a hydrophobic liquid supply unit 112 and the ultrapure water supply unit 111 according to the nature of the wafer. And spraying ultrapure water or liquid by controlling a valve located at the liquid supply part 112. Meanwhile, the gas injection port 120 is connected to the nitrogen supply line 122 to inject nitrogen gas by controlling a valve located in the nitrogen gas supply unit 121.

It is apparent to those skilled in the art that the present invention is not limited to the above embodiments and can be practiced in various ways without departing from the technical spirit of the present invention. It is.

1 is a block diagram showing a pusher of the chemical mechanical polishing apparatus according to the present invention,

2 is a cross-sectional view of the pusher of the chemical mechanical polishing apparatus according to the present invention;

Figure 3 is a schematic diagram showing a process of seating a wafer on the pusher of the chemical mechanical polishing apparatus according to the present invention.

<Explanation of symbols for the main parts of the drawings>

10: Wafer 20: CMP head

100: pusher 110: liquid injection port

120: gas injection hole 130: pusher stage

Claims (4)

In the pusher of the chemical mechanical polishing apparatus, the wafer is separated from the CMP head and seated in order to transfer the polished wafer of the chemical mechanical polishing process to the next process, Pusher of chemical mechanical polishing apparatus, characterized in that the liquid injection port and the gas injection port is formed alternately around the edge of the pusher at regular intervals in order to reduce the physical impact when the wafer is separated from the CMP head falling into the pusher . The method of claim 1, The liquid injection port is connected to an ultrapure water supply line of a hydrophilic ultra pure water (DI) water supply unit and a liquid supply line of a hydrophobic liquid supply unit, and sprays the hydrophobic liquid when the wafer is hydrophilic, and hydrophilic ultrapure water when the wafer is hydrophobic. (DI) A pusher of a chemical mechanical polishing apparatus, characterized by spraying water. 3. The method of claim 2, The pusher of the chemical mechanical polishing apparatus, characterized in that the hydrophobic liquid is tetramethammonium hydroxide (Tetramethyammonium hydroxide). The method of claim 1, The gas injection port is connected to the nitrogen supply line of the nitrogen gas supply unit pusher of the chemical mechanical polishing apparatus, characterized in that for injecting nitrogen gas.

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