KR100744528B1 - Apparatus for rf powered plasma enhanced atomic layer deposition using showerhead having gas separative type and the method - Google Patents

Abstract

A plasma atomic layer deposition apparatus using a shower head of a gas separative type and a method thereof are provided to minimize loss of plasma by directly applying an RF power to the shower head. A gas supply unit(100) has first and second precursor supply sources(110,120), a purge gas supply source(130), an inert gas supply source(140), and plural valves for adjusting flow rate of each gas. A shower head(200) has first and second precursor supply pipes, and mixture spraying holes for spraying first and second precursors, a purge gas and an inert gas into a reaction chamber(1). A power applying unit is positioned at an outside of the shower head. An exhaust unit(400) has an exhaust pump.

Description

Apparatus for RF powered plasma enhanced atomic layer deposition using showerhead having gas separative type and the method}

1 is a schematic view showing an ALD device using a gas separation showerhead to which RF power is applied according to the present invention.

Figure 2a schematically shows an embodiment of a showerhead portion including an insulator of an ALD device using a gas separation showerhead to which RF power is applied according to the present invention.

FIG. 2B is a three-dimensional view of FIG. 2A

Figure 3a is a view showing another embodiment of the showerhead portion including the insulator of the ALD device using a gas separation showerhead to which RF power is applied according to the present invention.

FIG. 3B is a three-dimensional view of FIG. 3A

4A and 4B illustrate an insulator portion and a ground portion of FIGS. 2A and 3A surrounding a shower head.

5 is a view showing an embodiment of a method for depositing an atomic layer using an ALD device using a gas separation showerhead to which RF power is applied according to the present invention.

6 is a view schematically showing a configuration for preventing backflow of gas in a showerhead of an ALD device using a gas separation showerhead to which RF power is applied according to the present invention.

<Explanation of symbols for main parts of the drawings>

1: reaction chamber 100: gas supply part

110: first precursor source 120: second precursor source

130: purge gas supply source 140: inert gas supply source

200: shower head portion 210: first precursor supply pipe

211: first precursor injection hole 220: second precursor supply pipe

221: second precursor injection hole 230: gas separation module

240: mixed gas injection module 241: insulator

242: ground portion 250: mixing nozzle

300: power on 400: exhaust

v / v: valve

The present invention relates to an atomic layer deposition apparatus and a method thereof in a semiconductor thin film deposition apparatus, and more particularly, to a plasma atomic layer deposition apparatus and a method using a gas separation type shower head to which RF power is applied.

As the integration of semiconductor devices progresses, a process with better step coverage is required compared to a conventional chemical vapor deposition (CVD) process in order to fill or apply a fine patterned structure. Atomic layer deposition (hereinafter referred to as ALD) process that can form a thin film with a uniform thickness while suppressing it as much as possible is mainly used.

ALD absorbs molecules on the surface of the wafer by chemically adhering and then replaces them by alternately adsorbing and replacing them, enabling ultra-layer-by-layer deposition and stacking oxide and metal thin films as thinly as possible. There is a characteristic. In addition, since it is possible to form excellent film quality at a lower temperature (500 ℃ or less) than CVD, it is a great advantage that it is suitable for system-on-chip (SoC) manufacturing.

For the general ALD process, since the reaction between the reactant and the deposition gas at the ALD process temperature is large, the choice of precursors is narrower than that of the CVD process. The method of depositing a thin film by improving this is used.

In the plasma atomic layer deposition process, applying a plasma to a reaction chamber in which a substrate is mounted may damage a semiconductor device or a substrate formed or being formed on an adjacent substrate, and in order to minimize the damage caused by the plasma, the plasma generation source may be removed from the substrate. It is common to use an independent remote plasma system.

However, the ALD apparatus used in the conventional remote plasma ALD process has a remote plasma chamber located outside the deposition chamber and the plasma efficiency is reduced due to recombination while supplying an ionized source through the supply line to the deposition chamber. The configuration of the supply line had a rather complicated problem.

In addition, the structure of the showerhead prevents the uniformity of process conditions due to the change of gas flow due to the presence of different final nozzles even when the deposition gas and the reaction gas are supplied separately, and when the shower head is sprayed, and the reaction time increases. There was a disadvantage.

The present invention has been proposed to solve the above problems, by applying RF power directly to the showerhead to generate a plasma to minimize the plasma loss due to the minimum path and to simplify the configuration of the gas supply line and the deposition gas and the reaction gas Separate injection and transport of the gas, the final injection of the deposition gas and the reaction gas using the same shower head to suppress the generation of by-products in the shower head using the same shower head, the gas flow in the chamber during atomic layer deposition It is an object of the present invention to provide an ALD apparatus and method using a gas separation shower head that can maintain the uniformity of the.

In order to achieve the above technical problem, the present invention provides a device for performing atomic layer deposition (hereinafter referred to as ALD) using a gas separation showerhead to which RF power is applied, the first precursor supplied with a first precursor. (precursor) a gas supply having a source, a second precursor source to which the second precursor is supplied, a purge gas source, an inert gas source and a plurality of valves to control the opening and closing of each gas; A first precursor supply pipe connected to the first precursor source and a second precursor supply pipe connected to the second precursor source, and a lower portion of the first precursor, the second precursor, a purge gas, and an inert gas into the reaction chamber. A shower head unit including a mixed injection hole separately injected and an insulator and including a mixed gas injection module to block the influence of the plasma generated from the power applying unit; A power applying unit positioned outside the shower head and applying a power having a predetermined frequency to the shower head to bring the reactor body into a plasma state, and an exhaust pump, wherein the purge gas is injected into the reaction chamber. And an exhaust unit for discharging residual gas inside the reaction chamber to the outside of the reaction chamber.

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

1 schematically shows an ALD apparatus using a gas separation type shower head to which RF power is applied according to the present invention, and includes a gas supply part 100, a shower head part 200, a power applying part 300, and an exhaust part 400. It is composed of

The gas supply unit 100 to which the deposition gas, the reactor gas, the purge gas, and the inert gas are supplied may include the first precursor source 110 to which the first precursor precursor1 is supplied, and the second precursor source to which the second precursor precursor2 is supplied. 120, a purge gas supply source 130, an inert gas supply source 140, and a plurality of valves (v / v 1 to v / v 4) capable of adjusting the opening and closing of each gas.

Figure 2a schematically shows a showerhead of the ALD device according to the present invention, the first precursor supply pipe 210, the second precursor supply pipe 220, gas separation module 230, mixed gas injection module 240, mixing The injection port 250 and the power applying unit 300 is composed of.

The first precursor supply pipe 210 and the second precursor supply pipe 220 are separated so that the first precursor and the second precursor can be separately supplied to the showerhead 200, and the gas separation module 230 includes the first precursor supply pipe. The first precursor and the second precursor are separated and provided to separate and spray the precursor and the second precursor, and the first precursor and the second precursor are not sprayed through separate injection holes, but through the mixed injection holes 250 jointly. It is injected into the reaction chamber (1).

The power applying unit 300 applies a predetermined power directly to the showerhead before the second precursor is supplied to the showerhead so that the sprayed second precursor is in a plasma state.

The mixed gas injection module 240 is positioned at the bottom of the showerhead of the present invention, and blocks the influence of the plasma generated from the power applying unit 300 so that the influence of the plasma is not affected when the reaction gas is supplied.

The mixed gas injection module 240 may be divided into two cases.

As shown in FIG. 2A, the mixed gas injection module 240 includes an insulator portion 241 such as Al ₂ O ₃ and an aluminum ground portion 242 positioned under the insulator portion 241 and FIG. 3A. As shown in the case, the mixed gas injection module 240 is composed of only an insulator such as Al ₂ O ₃ .

Although there may be no ground portion as shown in FIG. 3A, when the ground portion 242 is present as shown in FIG. 2A, the influence of the plasma blocked by the insulator portion 241 is further lowered so that the plasma does not affect the substrate or the like.

The insulator used in the present invention includes a ceramic material series such as Al ₂ O ₃ and AlN and a polymer material series such as Teflon. That is, any one may be a ceramic material such as Al ₂ O ₃ , AlN or a polymer material such as Teflon, or may be a composite of a ceramic material and a polymer material.

The shape of the mixed gas injection module 240 may be made in various shapes to suit the purpose of the process, it is possible to produce the effect by the various shapes of the plurality of cavity electrodes of the prior invention as it is.
FIG. 2B is a three-dimensional view of a part of the gas separation module 230 and the mixed gas injection module 240 of the shower head unit shown in FIG. 2A.
Referring to FIG. 2B, the second precursor supply pipe 220 is connected to each of the plurality of second precursor injection holes 221 positioned in the center of the mixing injection hole 250, and the first precursor supply pipe 210 is connected to the second precursor. It is connected to each of the plurality of first precursor injection holes 211, which are spaces surrounding the injection holes 221, and the plurality of first precursor injection holes 211 and the plurality of second precursor injection holes 221 are separated from each other. It is.
In addition, the second precursor injection hole 221 may adjust the position of the end from the upper plate to the lower plate of the mixed gas injection module 240, it can also adjust the width.

The purge gas source 130 of the gas supply unit 100 is connected to any one of the first precursor supply pipe 210 or the second precursor supply pipe 220 of the shower head 200, and the first precursor during deposition. Alternatively, a predetermined purge gas is injected into the chamber 1 through the mixing injection hole 250 after the second precursor is injected or to prevent the backflow.

The exhaust unit 400 having the exhaust pump discharges residual gas, etc. in the reaction chamber 1 to the outside when the purge gas is injected into the reaction chamber 1, and also the first precursor of the gas supply unit 100. Directly connected to either source 110 or second precursor source 120, the second precursor from the second precursor source 120 does not pass through the reaction chamber 1 when the first precursor is injected into the showerhead 200. If the second precursor is injected into the showerhead, the first precursor flows directly from the first precursor source 110 to the exhaust pump without passing through the reaction chamber 1.

5 is a diagram illustrating an atomic layer deposition method using plasma according to an embodiment of the present invention.

First, the deposition gas is adsorbed onto the surface of the substrate through the first precursor supply pipe 210 (S501), and after the adsorption is completed, excess deposition gas is removed through the purge process (S502).

Next, RF power is directly applied to the showerhead 200 to make a plasma state (S503), and supply a reaction gas through the second precursor supply pipe 220 to cause a reaction with the deposition gas (S504).

After the film is formed through the reaction, the RF power is cut off to form a plasma OFF state (S505), and the excess gas and impurities in the chamber are removed through a purge process (S506).

Table 1 shows an example of the operation sequence of the plurality of valves (v / v 1 ~ v / v 4) in the atomic layer deposition method shown in FIG.

TABLE 1

division fair v / v 1 v / v 2 v / v 3-1 v / v 3-2 v / v 4 S501 First precursor supply RUN DIVERT CLOSE CLOSE CLOSE S502 Fudge DIVERT DIVERT OPEN CLOSE CLOSE S503 RF power DIVERT DIVERT CLOSE CLOSE OPEN S504 Second precursor supply DIVERT RUN CLOSE CLOSE OPEN S505 RF Power Off DIVERT DIVERT CLOSE CLOSE CLOSE S506 Fudge DIVERT DIVERT CLOSE OPEN CLOSE

On the other hand, Table 2 shows the operation sequence of the valve in the configuration for preventing the back flow in the shower head shown in FIG.

TABLE 2

division fair v / v 1 v / v 2 v / v 3-1 v / v 3-2 v / v 4 S501 First precursor supply RUN DIVERT CLOSE OPEN CLOSE S502 Fudge DIVERT DIVERT OPEN OPEN CLOSE S503 RF power DIVERT DIVERT OPEN CLOSE OPEN S504 Second precursor supply DIVERT RUN OPEN CLOSE OPEN S505 RF Power Off DIVERT DIVERT OPEN CLOSE CLOSE S506 Fudge DIVERT DIVERT OPEN OPEN CLOSE

Where RUN means that it flows into the reaction chamber 1, OPEN means that the valve is open, CLOSE means that the valve is closed, and DIVERT means that it flows directly into the exhaust pump 30 without flowing into the reaction chamber 1. .

The technical spirit of the present invention has been described above with reference to the accompanying drawings. However, the present invention has been described by way of example only, and is not intended to limit the present invention. In addition, it is apparent that any person having ordinary knowledge in the technical field to which the present invention belongs may make various modifications and imitations without departing from the scope of the technical idea of the present invention.

As described above, the ALD apparatus using the gas separation type showerhead to which the RF power is applied according to the present invention generates plasma by applying RF power directly to the showerhead to minimize plasma loss through supply through a minimum path, and Compared to the gas supply line in the ALD process through the remote plasma, the configuration can be simplified, there is little damage by plasma in the substrate, and the deposition gas and the reactant gas do not react with each other in the shower head, so that the by-products are generated inside the shower head. There is an advantage that can be suppressed.

In addition, the ALD apparatus using a gas separation type showerhead to which RF power is applied according to the present invention can maintain uniformity of gas flow in the chamber in all process sequences due to the same final injection hole through which the deposition gas and the reactor gas are injected in the shower head. And, there is an advantage that can shorten the overall deposition process time.

Claims (19)

An apparatus for atomic layer deposition (hereinafter referred to as ALD) using a gas separation showerhead to which RF power is applied, A gas supply unit including a first precursor source supplied with a first precursor, a second precursor source supplied with a second precursor, a purge gas supply source, an inert gas supply source, and a plurality of valves for controlling opening and closing of each gas; A first precursor supply pipe connected to the first precursor source and a second precursor supply pipe connected to the second precursor source, and a lower portion of the first precursor, a second precursor, a purge gas, and an inert gas is inside the reaction chamber. A shower head unit including a mixed injection hole and an insulator which are separately injected into the mixing unit and having a mixed gas injection module that blocks the influence of the plasma generated from the power applying unit; A power applying unit located outside the shower head and applying a power having a predetermined frequency to the shower head to bring the reactor body into a plasma state; and An exhaust pump having an exhaust pump and discharging the residual gas in the reaction chamber to the outside of the reaction chamber when the purge gas is injected into the reaction chamber; ALD device using the head. The method of claim 1, wherein the mixed gas injection module An ALD device using a gas separation shower head to which RF power is applied, characterized in that it is composed of only an insulator to form a plurality of the mixing nozzles therein. The method of claim 1, wherein the mixed gas injection module An ALD device using a gas separation shower head to which RF power is applied, including the insulator portion and an aluminum ground portion positioned below the insulator portion to form a plurality of the mixing nozzles therein. The method of claim 1, wherein the second precursor supply pipe The first precursor supply pipe is connected to each of the plurality of first precursor injection holes located in the center of the mixing injection hole, the first precursor supply pipe is connected to each of the plurality of first precursor injection holes located in the center of the second precursor injection hole, And a plurality of first precursor injection holes and the plurality of second precursor injection holes are separated from each other. The method of claim 4, wherein the second precursor injection hole ALD device using a gas separation shower head is applied RF power, characterized in that the position of the end can be adjusted from the top plate to the bottom plate of the mixed gas injection module, the width can also be adjusted. delete delete delete The method of claim 1, wherein the power applying unit ALD device using a gas separation shower head is applied RF power, characterized in that the RF power directly applied to the shower head. The method of claim 1 wherein the purge gas source is An ALD device using a gas separation showerhead to which RF power is applied, characterized in that it is connected to at least one of the first precursor supply pipe and the second precursor supply pipe. The method of claim 1, wherein the purge gas And the first precursor or the second precursor is injected into the reaction chamber through the mixing nozzle, and the ALD device using the gas separation type shower head to which RF power is applied. The method of claim 1, wherein the exhaust unit RF power is directly connected to the first precursor source, such that when the second precursor is injected, the first precursor flows directly from the first precursor source to the exhaust pump without passing through the reaction chamber. ALD apparatus using an applied gas separation shower head. The method of claim 1, wherein the exhaust unit RF power is connected directly to the second precursor source to cause the second precursor to flow directly from the second precursor source to the exhaust pump without passing through the reaction chamber when the first precursor is injected. ALD apparatus using an applied gas separation shower head. The method of claim 1, wherein the insulator is ALD apparatus using a gas separation type shower head is applied RF power, characterized in that any one of a ceramic material or a polymer material or a composite of a ceramic material and a polymer material. In the atomic layer deposition method using plasma using an ALD device using a gas separation shower head to which the RF power according to claim 1 is applied, (a) adsorbing the deposition gas to the substrate surface through the first precursor supply pipe; (b) removing excess of the deposition gas through a purge process after the adsorption is completed; (c) applying RF power directly to the showerhead to make the Plasma ON state; (d) supplying a reactor gas through a second precursor supply pipe to cause a reaction with the deposition gas; (e) cutting off RF power to make the Plasma OFF state; And (f) removing excess gas and impurities in the chamber through a purge process. The method of claim 15, A method of depositing an atomic layer using plasma, characterized in that to form the material layer by repeating steps (a) to (f) for the reactants required for forming the material layer to deposit the desired material. The method of claim 15, wherein step (a) Opening the purge gas supply valve connected to the second precursor supply pipe flows a small amount of purge gas to prevent the reverse flow of the first precursor, atomic layer deposition method using a plasma The method of claim 15, wherein step (d) Opening the purge gas supply valve connected to the first precursor supply pipe flows a small amount of purge gas to prevent the reverse flow of the second precursor, atomic layer deposition method using a plasma delete

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