JP2007067253A - Film forming apparatus and method of manufacturing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable to highly accurately execute composition control of a multiple system film while suppressing temperature rise in film forming. <P>SOLUTION: A deposition source 7 is heated with a heater 6 while performing vacuation of the inside of a chamber 1 to perform film forming processing of a semiconductor wafer W by evaporation. At the same time, a sputter gas G1 and a reaction gas G2 are supplied to the chamber 1, and a high-frequency voltage is applied to a target 2. In this way, plasma PZ is generated into the chamber 1, and film forming processing of the semiconductor wafer W is performed by sputtering while performing film forming processing of the wafer W by evaporation. Thus, the multiple system film is formed on the semiconductor wafer W. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a film forming apparatus and a method for manufacturing a semiconductor device, and is particularly suitable for application to a method for forming a multi-element film.

In a conventional semiconductor device, a method such as sputtering or vapor deposition is used to form a thin film such as a metal film or an insulating film on a semiconductor wafer.
For example, in Patent Document 1, in order to obtain an excellent stoichiometric thin film having a high film density by atomic layer deposition, a first reactant is introduced into a chamber loaded with a substrate. The first reactant is chemisorbed onto the substrate and purged or pumped into the chamber to remove the first reactant physically adsorbed on the chemisorbed first reactant and into the chamber. A method is disclosed in which one reactant is injected again and the first reactant is chemisorbed onto the substrate so as to be dense.
JP 2000-54134 A

  However, the method of forming a multi-element film on a semiconductor wafer by sputtering has a problem in that the composition of the multi-element film cannot be controlled because the sputter yield varies from element to element. For example, in the case of a Ti—Al—N-based film used for a hydrogen barrier film or an oxygen barrier film of a nonvolatile memory, the sputter yield differs between Ti and Al, so the composition control of the Ti—Al—N-based film can be controlled. Can not. In addition, since Ti and Al have significantly different melting points, an alloy target having a uniform composition cannot be obtained. As a result, since the composition of the Ti—Al—N film cannot be optimized by sputtering, there is a problem that the hydrogen barrier property and the oxygen barrier property of the Ti—Al—N film deteriorate.

On the other hand, in the method of forming a multi-element film on a semiconductor wafer by vapor deposition, high temperature is required to form a refractory metal, and high energy is required for film formation. Furthermore, since a high temperature substance adheres to the surface of the semiconductor wafer, there is a problem that it cannot be applied due to the heat resistance of the element and the base material.
Accordingly, an object of the present invention is to provide a film forming apparatus and a semiconductor device manufacturing method capable of accurately controlling the composition of a multi-component film while suppressing a temperature rise during film formation.

In order to solve the above-described problem, according to a film formation apparatus according to one embodiment of the present invention, a chamber for isolating a film formation target from the atmosphere, and a film formation process for the film formation target placed in the chamber are performed. Vapor deposition means for performing vapor deposition, and sputtering means for performing film formation processing of the film formation target by sputtering during film formation processing by the vapor deposition means.
This makes it possible to change the composition ratio of the multi-component film by individually controlling the deposition conditions and the sputtering conditions, and has a high melting point even when the multi-component film contains a high melting point material. There is no need to heat to a high temperature to evaporate the material. For this reason, it is possible to accurately control the composition of the multi-component film while suppressing the temperature rise during the film formation, and the composition of the multi-component film can be optimized.

  In addition, according to the film forming apparatus of one embodiment of the present invention, a chamber for isolating a film formation target from the atmosphere, an exhaust unit for evacuating the chamber, and a holding unit for holding a vapor deposition source in the chamber Heating means for evaporating the vapor deposition source by heating the vapor deposition source, a target installed in the chamber, a supply means for supplying gas into the chamber, and discharging the gas Sputtering means for sputtering the target.

Thereby, it becomes possible to perform vapor deposition and sputtering simultaneously in the same chamber, and the composition ratio of the multi-component film can be changed by individually controlling the vapor deposition conditions and the sputtering conditions. For this reason, even when the sputter yield varies from element to element, the composition control of the multi-element film can be performed with high accuracy, and the composition of the multi-element film can be optimized.
In addition, according to the method for manufacturing a semiconductor device according to one aspect of the present invention, a step of placing a semiconductor wafer in a chamber in which a deposition source and a target are installed, and heating the deposition source, the semiconductor wafer And a step of performing a film forming process of a film formation target by sputtering by performing sputtering of the target during the film forming process by vapor deposition. .

Thereby, it becomes possible to perform vapor deposition and sputtering simultaneously in the same chamber, and the composition ratio of the multi-component film can be changed by individually controlling the vapor deposition conditions and the sputtering conditions. For this reason, even when the sputter yield varies from element to element, the composition control of the multi-element film can be performed with high accuracy, and the composition of the multi-element film can be optimized.
According to the method for manufacturing a semiconductor device of one embodiment of the present invention, a step of forming an element isolation insulating film on the semiconductor wafer, and a field effect transistor in an active region isolated by the element isolation insulating film Forming a first interlayer insulating film on the field effect transistor, forming a lower electrode on the interlayer insulating film, and forming a ferroelectric film on the lower electrode A hydrogen barrier property or an oxygen barrier property by combining a step, a step of forming an upper electrode on the ferroelectric film, a step of forming a second interlayer insulating film on the upper electrode, and vapor deposition and sputtering. And a step of forming a multi-element film having a thickness on the second interlayer insulating film.

  This makes it possible to perform vapor deposition and sputtering simultaneously in the same chamber, and change the composition ratio of the multi-component film having hydrogen barrier properties or oxygen barrier properties by individually controlling the vapor deposition conditions and the sputtering conditions. be able to. For this reason, even when the sputter yield varies from element to element, it is possible to accurately control the composition of a multi-element film having hydrogen barrier properties or oxygen barrier properties, and hydrogen in a nonvolatile memory using a ferroelectric film can be obtained. A barrier property or an oxygen barrier property can be secured.

Hereinafter, a film forming apparatus and a method for manufacturing a semiconductor device according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view showing a schematic configuration of a film forming apparatus according to an embodiment of the present invention.
In FIG. 1, the chamber 1 is provided with an exhaust pipe 11 that exhausts the inside of the chamber 1, and supply pipes 12 and 13 that supply the sputtering gas G <b> 1 and the reaction gas G <b> 2 into the chamber 1, respectively. An electrostatic chuck 4 that holds the semiconductor wafer W is provided in the chamber 1. In the chamber 1, a crucible 5 in which a vapor deposition source 7 is placed is installed, and a heater 6 for heating the vapor deposition source 7 is provided. Further, a sputtering target 2 is disposed in the chamber 1, and a high frequency power source 3 for applying a high frequency voltage is connected to the target 2.

  When a multi-element film is formed on the semiconductor wafer W, the semiconductor wafer W is carried into the chamber 1 and the semiconductor wafer W is fixed in the chamber 1 via the electrostatic chuck 4. Then, while evacuating the chamber 1, the vapor deposition source 7 is heated by the heater 6, and the film forming process of the semiconductor wafer W is performed by vapor deposition. Further, a sputtering gas G1 and a reactive gas G2 are supplied into the chamber 1, respectively. For example, argon gas can be used as the sputtering gas G1. Then, a plasma PZ is generated in the chamber 1 by applying a high-frequency voltage to the target 2, and the semiconductor wafer W film forming process is performed by sputtering while the semiconductor wafer W film forming process is performed by vapor deposition. Thus, a multi-element film is formed on the semiconductor wafer W.

  This makes it possible to change the composition ratio of the multi-component film by individually controlling the heating temperature of the vapor deposition source 7, the power applied to the target 2, and the flow rate of the reaction gas G2, and the multi-component film Even when a high melting point substance is contained, it is not necessary to heat to a high temperature for evaporating the high melting point substance. Therefore, it is possible to accurately control the composition of the multi-component film while suppressing the temperature rise during the film formation, and the multi-component film having the optimized composition can be formed on the semiconductor wafer W. .

For example, by using Al as the vapor deposition source 7, Ti as the target 2, and N ₂ as the reaction gas G ₂ , Ti—Al—N is formed on the semiconductor wafer W while arbitrarily controlling the composition ratio of Ti, Al, and N. A film can be formed, and a Ti—Al—N-based film can be used as the hydrogen barrier film or the oxygen barrier film. Specifically, a Ti _x N _y —TiAl—AlN film can be formed while x and y can be arbitrarily set.

Further, by using B as the vapor deposition source 7, W as the target 2, and N ₂ as the reaction gas G2, the BN—WN film is formed on the semiconductor wafer W while arbitrarily controlling the composition ratio of B, W, and N. And a BN-WN film can be used as the barrier film of the tungsten plug.
Further, by using Si as the vapor deposition source 7, Ta as the target 2, and N ₂ as the reaction gas G2, the composition ratio of Ta, Si, and N is arbitrarily controlled, and Ta—Si—N is formed on the semiconductor wafer W. A system film can be formed, and a Ta—Si—N system film can be used as the gate electrode.

Further, an oxynitride film can be formed by using N ₂ + O ₂ or N ₂ O as the reactive gas G2.
As a sputtering method used in combination with vapor deposition, DC sputtering, magnetron sputtering, bias sputtering, or the like may be used in addition to high-frequency sputtering. Here, as a device configuration, the positional relationship between the semiconductor wafer W and the target 2 is a parallel plate type, and a side sputtering method is preferable. Thereby, the generation of particles can be suppressed, and the film formation efficiency can be improved.

FIG. 2 is a cross-sectional view showing a schematic configuration of the nonvolatile semiconductor memory device according to the embodiment of the present invention.
In FIG. 2, an element isolation insulating film 102 is formed on a semiconductor substrate 101. A gate electrode 104 is formed in the active region isolated by the element isolation insulating film 102 via the gate insulating film 103, and a source layer 105a and a drain layer arranged so as to sandwich the gate electrode 104 therebetween. 105 b is formed on the semiconductor substrate 101.

  An interlayer insulating film 106 is formed on the gate electrode 104, and a capacitor in which the upper and lower sides of the ferroelectric film 108 are sandwiched between the upper electrode 109 and the lower electrode 107 is formed on the interlayer insulating film 106. . Further, a barrier film 111 is formed on the upper electrode 109 via an interlayer insulating film 110, and an interlayer insulating film 112 is formed on the barrier film 111. An opening P1 exposing the drain layer 105b is formed in the interlayer insulating films 106 and 112, and one end and the other end of the upper electrode 109 are exposed in the interlayer insulating films 110 and 112 and the ferroelectric film 108, respectively. Opening portions P2 and P3 are formed.

  Further, wiring layers H1 and H2 are formed on the interlayer insulating film 112. The wiring layer H1 is connected to the drain layer 105b through the opening P1 and is connected to one end of the upper electrode 109 through the opening P2. Has been. The wiring layer H2 is connected to the other end of the upper electrode 109 through the opening P3. An interlayer insulating film 113 is formed on the wiring layers H 1 and H 2, and a barrier film 114 is formed on the interlayer insulating film 113.

  Here, as the barrier films 111 and 114, Ti—Al—N-based films can be used, and the barrier films 111 and 114 can have a hydrogen barrier property or an oxygen barrier property. Further, when forming the barrier films 111 and 114, the composition ratio of the Ti-Al-N-based film can be arbitrarily determined by simultaneously performing deposition and sputtering in the same chamber while individually controlling the deposition conditions and the sputtering conditions. Can be changed. For this reason, even when the sputtering yield is different between Ti and Al, the composition control of the Ti—Al—N film can be performed with high accuracy, and the hydrogen barrier property of the nonvolatile memory using the ferroelectric film 108 or Oxygen barrier properties can be ensured.

1 is a cross-sectional view showing a schematic configuration of a film forming apparatus according to an embodiment of the present invention. 1 is a cross-sectional view illustrating a configuration of a nonvolatile semiconductor memory device according to an embodiment of the present invention.

Explanation of symbols

  1 chamber, 2 target, 3 high frequency power supply, 4 electrostatic chuck, 5 crucible, 6 heater, 7 evaporation source, 11 exhaust pipe, 12, 13 supply pipe, W semiconductor wafer, 101 semiconductor substrate, 102 element isolation insulating film, 103 Gate insulating film, 104 gate electrode, 105a source layer, 105b drain layer, 106, 110, 112, 113 interlayer insulating film, 107 lower electrode, 108 ferroelectric film, 109 upper electrode, 111, 114 barrier film, H1, H2 Wiring layer, P1, P2, P3 opening

Claims (4)

A chamber for isolating the deposition target from the atmosphere;
Vapor deposition means for performing a film formation process of a film formation target placed in the chamber by vapor deposition;
A film forming apparatus comprising: sputtering means for performing film forming processing of the film forming target by sputtering during film forming processing by the vapor deposition means. A chamber for isolating the deposition target from the atmosphere;
Exhaust means for evacuating the chamber;
Holding means for holding a vapor deposition source in the chamber;
Heating means for evaporating the deposition source by heating the deposition source;
A target installed in the chamber;
Supply means for supplying gas into the chamber;
A film forming apparatus comprising: sputtering means for sputtering the target by discharging the gas. Placing a semiconductor wafer in a chamber in which a deposition source and a target are installed;
Heating the vapor deposition source to perform deposition of the semiconductor wafer by vapor deposition;
A method of manufacturing a semiconductor device, comprising: performing sputtering on the target during film formation by vapor deposition to perform film formation on the target of film formation by sputtering. Forming an element isolation insulating film on the semiconductor wafer;
Forming a field effect transistor in an active region isolated by the element isolation insulating film;
Forming a first interlayer insulating film on the field effect transistor;
Forming a lower electrode on the interlayer insulating film;
Forming a ferroelectric film on the lower electrode;
Forming an upper electrode on the ferroelectric film;
Forming a second interlayer insulating film on the upper electrode;
And a step of forming a multi-element film having a hydrogen barrier property or an oxygen barrier property on the second interlayer insulating film by using vapor deposition and sputtering together.

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