KR19980026071A - Semiconductor manufacturing equipment using plasma - Google Patents

Abstract

Disclosed is a manufacturing apparatus for a semiconductor device using plasma. This equipment is a closed chamber having a ground potential, a gas injection tube for injecting a process gas into the chamber from outside by communicating with a predetermined area of the chamber wall, and a chuck installed at the bottom of the chamber to place a wafer. A power source for forming a plasma in the chamber by applying a predetermined electric power to the electrode, and a discharge pipe connected to a predetermined area of the chamber bottom to adjust the pressure in the chamber and discharge the reacted gas in the chamber. And a suction port located below the electrode edge and connected to a discharge pipe in the chamber to suck the reacted gas and air in the chamber, the plasma equipment being disposed between the suction port and the edge of the electrode and opposite to the electrode. Further comprising an additional electrode to which the potential is applied . Accordingly, particles formed at the edge of the electrode may be discharged to the outside of the chamber during plasma formation, thereby preventing particles adsorbed as contaminants on the surface of the wafer during the plasma process.

Description

Semiconductor manufacturing equipment using plasma

The present invention relates to equipment used in the manufacture of semiconductor devices, and more particularly, to equipment using plasma.

The equipment used to manufacture a semiconductor device includes ion implantation equipment for injecting desired impurities into a predetermined region of the wafer, a furnace for growing a thermal oxide film, a deposition equipment for depositing a conductive film or an insulating film on the wafer, There are exposure equipment and etching equipment for patterning the deposited conductive film or insulating film in a desired form. Among these equipments, as a device for depositing a predetermined material film on a wafer or etching a predetermined material film formed on a wafer, a plasma device for forming a plasma in a closed chamber in a vacuum state and injecting a reactive gas to deposit or etch a material film is widely used. It is used. This is because when the material film is deposited using plasma, the process may be performed at a low temperature at which impurities in the impurity region formed on the wafer are no longer diffused, and the thickness uniformity of the material film formed on the large diameter wafer is excellent. Likewise, when a predetermined material film formed on the wafer is etched using plasma, the etch rate uniformity is excellent throughout the wafer.

1 is a schematic diagram for explaining a conventional plasma equipment.

Referring to FIG. 1, a conventional plasma apparatus communicates with a hermetically sealed chamber 1 having a ground potential and a predetermined region of an upper wall or sidewall of the chamber 1, so that a process gas, ie, a process gas, is stored in the chamber 1 from the outside. A gas injection tube 3 for injecting a reactive gas, an electrode 5 installed below the chamber 1 and serving as a chuck on which a wafer is placed, and a predetermined electric power applied to the electrode 5 to provide a chamber ( 1) an external vacuum in communication with a power source 7 for forming a plasma in the chamber, and a predetermined area of the bottom of the chamber 1 for controlling the pressure in the chamber 1 and for discharging the reacted gas in the chamber 1; A discharge pipe 9 connected to a pump (not shown) and a suction port 11 installed at an end of the discharge pipe 9 inside the chamber 1 to suck process gas and air in the chamber 1. do. Here, the suction port 11 is located below the edge of the electrode (5).

In order to form a plasma in the chamber 1 of the conventional plasma equipment configured as described above, a gas such as argon is injected into the chamber 1 in a high vacuum state, and a high voltage is applied to the electrode 5 to discharge it. At this time, the fact that particles are generated in the chamber 1 is widely known, and these particles act as contaminating particles to contaminate the wafer surface and consequently reduce the production yield of semiconductor devices.

Accordingly, it is an object of the present invention to provide a plasma apparatus capable of removing particles generated in a chamber by installing an additional electrode induced with a polarity opposite to the electrode under the electrode edge on which the wafer is placed.

1 is a schematic diagram for explaining a conventional plasma equipment.

2 is a schematic view for explaining the plasma equipment of the present invention.

3 is a graph showing a voltage waveform applied to the electrode of FIG. 2 and a potential induced in the additional electrode with time.

In order to achieve the above object, the plasma apparatus of the present invention includes a closed chamber having a ground potential, a gas injection tube communicating with a predetermined region of the chamber wall, and injecting a process gas into the chamber from the outside; An electrode installed in the lower part, which serves as a chuck on which the wafer is placed, a power source for applying a predetermined electric power to the electrode to form a plasma in the chamber, and adjusting the pressure in the chamber and discharging the reacted gas in the chamber In the plasma equipment having a discharge pipe connected to a predetermined area of the chamber bottom, and the suction pipe is located below the electrode edge and connected to the discharge pipe in the chamber to suck the reacted gas and air in the chamber, the suction port and the electrode Installed between the edges and applied with a potential opposite to the electrode It is characterized by further comprising an additional electrode.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a schematic view for explaining the plasma equipment of the present invention. Here, the parts denoted by the same reference numerals as those of FIG. 1 mean the same parts.

Referring to FIG. 2, the plasma apparatus of the present invention communicates with a closed chamber 1 having a ground potential and a predetermined region of the wall of the chamber 1 so that a process gas, that is, a reaction, is formed in the chamber 1 from the outside. A gas injection tube 3 for injecting a gas, an electrode 5 installed below the chamber 1 and serving as a chuck on which a wafer is placed, and a predetermined power is applied to the electrode 5 to the chamber A power source 7 for forming a plasma in the chamber 1, and a discharge pipe communicating with a predetermined region of the bottom of the chamber 1 for controlling the pressure in the chamber 1 and for discharging the reacted gas in the chamber 1; (9), an inlet (11) located below the edge of the electrode (5) and connected to the discharge pipe (9) in the chamber (1) to suck the reacted gas and air in the chamber (1), and the inlet ( 11) and an additional electrode 13 provided between the edge of the electrode 5 .

3 is a graph showing the voltage waveform applied to the electrode 5 and the potential induced in the additional electrode 13 over time to form a plasma in the chamber 1 of FIG. The vertical axis of the graph shows the pulse waveform applied to the electrode 5, and the graph shown below shows the waveform of the potential induced in the additional electrode 13 by the pulse waveform applied to the electrode 5. . Here, the section denoted by reference numeral T1 represents the time when a predetermined voltage is applied to the electrode 5, and the section denoted by the reference symbol T2 indicates the time when the ground potential is applied to the electrode 5.

Referring to Figures 2 and 3 will be described the plasma formation principle of the plasma equipment according to the present invention.

First, argon gas is injected from the outside through the gas injection tube 3 into the chamber 1 in a high vacuum state, and an argon plasma is formed on the electrode 5 by applying a pulse waveform voltage to the electrode 5. . An argon plasma contains electrons that are negative charges and argon ions that are positive charges. At this time, as the argon gas is injected into the chamber 1, the pressure in the chamber 1 changes rapidly, and particles are generated according to the pressure change. These particles are formed on the edge of the argon plasma formed on the electrode 5, that is, on the edge of the electrode 5, and are negatively charged during the time T1 at which a predetermined voltage is applied to the electrode 5. Distributed in a state. At this time, the additional electrode 13 has the same ground potential as the wall of the chamber 1 as shown in FIG. Next, during the time T2 at which the electrode 5 is grounded, a positive voltage is applied to the additional electrode 13 so that the negatively charged particles move toward the additional electrode 13. . As such, the particles moving toward the additional electrode 13 are sucked into the inlet 11 installed under the additional electrode 13 and discharged to the outside of the chamber 1. Here, the time T1 is preferably 20 to 10,000 μsec in order to sufficiently charge the particles (−), and the time (T2) corresponds to the time taken to neutralize the negatively charged particles. It is preferable that it is 100-10,000 microseconds.

The present invention is not limited to the above embodiments, and modifications and improvements are possible at the level of those skilled in the art.

As described above, according to the present invention, by installing an additional electrode below the edge of the electrode having a potential opposite to the voltage applied to the electrode, it is possible to discharge the particles generated during plasma formation to the outside of the chamber. Therefore, it is possible to prevent the particles acting as contaminating particles on the wafer during the plasma process, thereby improving the yield of the semiconductor device.

Claims (1)

An airtight chamber having a ground potential, a gas injection tube communicating with a predetermined region of the chamber wall to inject a process gas into the chamber from the outside, and an electrode installed under the chamber to serve as a chuck for placing a wafer A power source for forming a plasma in the chamber by applying a predetermined electric power to the electrode, a discharge pipe communicating with a predetermined region of the bottom of the chamber to adjust the pressure in the chamber and discharge the reacted gas in the chamber; In the plasma equipment having a suction port located below the electrode edge and connected to the discharge pipe in the chamber to suck the reacted gas and air in the chamber, And an additional electrode disposed between the suction port and an edge of the electrode and to which an electric potential opposite to the electrode is applied.