JP2004022857A - Apparatus and method for processing substrate and method of manufacturing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate processing apparatus which is capable of surely preventing defects in various patterns based on lithography by preventing the unwanted decomposited products from occurring in a hydrophobic treatment and by suppressing resist pattern defects. <P>SOLUTION: The substrate processing apparatus is composed of a closed chamber 1 where a semiconductor substrate 11 is installed, an HMDS bubbler 2 storing HMDS, a vaporizing gas inlet 3 which introduces nitrogen gas as evaporating gas to HMDS inside the HMDS bubbler 2 to evaporate the HMDS, a silica gel pipe 4 which is provided between the vaporizing gas inlet 3 and the HMDS bubbler 2 to remove moisture from the nitrogen gas sent out through the vaporizing gas inlet 3, and a hydrophobic treating agent outlet 5 through which the vaporized HMDS is sent onto the surface of the substrate 11. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a processing apparatus and a processing method for a substrate represented by a semiconductor substrate, and a method for manufacturing a semiconductor device to which the processing method is applied.
[0002]
[Prior art]
In recent years, high integration of semiconductor devices has been increasingly advanced, and fine processing in a manufacturing process has become more sophisticated. Accordingly, it has been strongly desired to reduce defects of various patterns such as electrodes and wirings and semiconductor substrates. Since various patterns of a semiconductor device are formed in accordance with this shape using a resist pattern formed by lithography as a mask, it is necessary to suppress the occurrence of defects in the resist pattern in order to prevent defects in the various patterns. is necessary.
[0003]
This defect in the resist pattern is generated depending on the surface condition of the substrate before applying the resist. To suppress this, it is necessary to realize a state in which a substance that reacts with the resist does not remain on the substrate. Cost.
[0004]
[Problems to be solved by the invention]
2. Description of the Related Art Conventionally, at the time of lithography, a hydrophobic treatment of a substrate is performed in order to improve adhesion between a resist and a substrate in a developing solution. However, in this case, there is a problem that a defect in the resist pattern is caused by alteration caused by a chemical reaction between the residue on the substrate after the hydrophobic treatment and the resist.
[0005]
The present invention has been made in view of the above problems, and prevents the generation of unnecessary decomposition products during the hydrophobic treatment, suppresses resist pattern defects, and reliably suppresses the occurrence of defects in various patterns based on lithography. It is an object of the present invention to provide a substrate processing method to be performed, a substrate processing apparatus for realizing the method, and a method of manufacturing a highly reliable and high-yield semiconductor device to which the method is applied.
[0006]
[Means for Solving the Problems]
As a result of intensive studies, the present inventor has reached various aspects of the invention described below.
[0007]
The substrate processing apparatus of the present invention includes a chamber in which a substrate to be non-processed is installed, storage means for storing a liquid hydrophobizing agent, and introducing a vaporizing gas into the hydrophobizing agent in the storage means. And a vaporizing means for vaporizing the hydrophobizing agent, a water removing means disposed between the vaporizing means and the storage means, for removing water from the vaporizing gas sent from the vaporizing means, Sending means for sending the vaporized hydrophobizing agent to the substrate provided in the chamber.
[0008]
In the substrate processing method of the present invention, the step of removing water from the vaporizing gas and the step of introducing the vaporized gas from which water has been removed into the stored liquid hydrophobizing agent to vaporize the hydrophobizing agent. And sending the vaporized hydrophobizing agent to a substrate to be non-processed to hydrophobize the substrate surface.
[0009]
The method of manufacturing a semiconductor device according to the present invention includes a step of forming a desired thin film on a surface of a semiconductor substrate, a step of hydrophobizing the surface of the semiconductor substrate, a step of applying a resist on the thin film, and processing the resist. Forming a resist pattern, and etching the thin film using the resist pattern as a mask, wherein the hydrophobizing step is a step of removing moisture from a vaporizing gas, and the step of removing the moisture from the vaporized gas. Introducing the gas for use into the stored liquid hydrophobizing agent, vaporizing the hydrophobizing agent, and sending out the vaporized hydrophobizing agent to a substrate to be non-processed, the surface of the semiconductor substrate And hydrophobizing.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
-Basic gist of the present invention-
First, the principle of operation of the present invention will be described.
The present invention is based on the premise that the surface of the semiconductor substrate terminated with a hydroxyl group is rendered hydrophobic by a cleaning treatment. Here, before applying the resist to the substrate, the surface of the substrate is subjected to a hydrophobic treatment, specifically, hexamethyldisilazane is used to replace the hydroxyl group on the substrate surface with a trimethylsilyl group. The substitution reaction of the hydroxyl group on the substrate surface with the trimethylsilyl group by the hexamethylsilazane lowers the surface energy of the substrate surface, and as a result, the adhesion of the resist in the developing solution is improved.
[0011]
However, in this case, when the resist is applied on the substrate, the decomposition product of hexamethyldisilazane used for the hydrophobic treatment of the substrate chemically reacts with the resist, thereby causing a defect in the resist pattern. This defect is remarkably confirmed after the formation of the resist pattern on the amorphous silicon film.
[0012]
Usually, the surface of the substrate is hydrophobized by bubbling with nitrogen gas to vaporize hexamethyldisilazane in a bubbling tank, which is a storage means for storing the hydrophobizing agent, and vaporizing the hexamethyldisilazane. Is introduced into a closed chamber in which the substrate is held, and the substrate is exposed to a hexamethyldisilazane atmosphere to perform a hydrophobic treatment on the substrate.
[0013]
The present inventor believes that the main cause of the above-described resist pattern defect is that trimethylsilanol, which is a decomposition product of hexamethyldisilazane due to a small amount of water present in nitrogen gas as a vaporizing gas chemically reacting with hexamethyldisilazane. It is considered that trimethylsilanol remains on the substrate after the hydrophobic treatment.
[0014]
It has been confirmed that this trimethylsilanol remains on the substrate even after heating at 200 ° C. or more after the hydrophobizing treatment, and the trimethylsilanol remaining on the substrate reacts with the resist to become hardly soluble in a developing solution, The resist remains in a portion where the resist does not normally remain, resulting in a resist pattern defect accompanied by the residue.
[0015]
In the present invention, the moisture in the vaporizing gas is removed immediately before introducing the vaporizing gas into the bubbling tank so that the decomposition product of hexamethyldisilazane does not remain on the substrate surface after the hydrophobic treatment. This makes it possible to perform the hydrophobic treatment without generating the decomposition product of hexamethyldisilazane, trimethylsilanol, and to prevent the occurrence of resist pattern defects due to trimethylsilanol.
[0016]
-Specific embodiment to which the present invention is applied-
Specific embodiments will be described based on the basic gist of the present invention described above.
Here, in manufacturing a semiconductor device, for example, a MOS transistor, substrate processing after forming a thermal oxide film serving as a gate insulating film and an amorphous silicon film serving as a gate electrode thereon will be described.
[0017]
FIG. 1 is a schematic diagram illustrating a schematic configuration of a substrate processing apparatus for performing substrate processing according to the present embodiment.
The substrate processing apparatus includes a closed chamber 1 having a hot plate 12 on which a silicon semiconductor substrate 11 to be non-processed is installed, and an HMDS bubbler 2 which is a bubbling tank for storing a liquid hydrophobizing agent hexamethyldisilazane. And a vaporizing gas introducing unit 3 which is a vaporizing means for introducing a nitrogen gas as a vaporizing gas into hexamethyldisilazane in the HMDS bubbler 2 to vaporize hexamethyldisilazane, and a vaporizing gas introducing unit 3 and an HMDS bubbler. A silica gel tube 4 which is a water removing means in which silica gel is disposed and which is provided with silica gel for removing water from the nitrogen gas sent out from the vaporized gas introducing section 3; Hexamethyldisilazane vaporized by the opening / closing control is sent to the surface of the semiconductor substrate 11 installed in the closed chamber 1. It is constituted by a hydrophobizing agent delivery unit 5.
[0018]
In the present embodiment, the substrate processing is performed using the substrate processing apparatus having the above-described configuration in a state as shown in FIG. Here, after a field oxide film 21 is formed in the element isolation region by the LOCOS method to define an active region, a thermal oxide film 31 serving as a gate insulating film and an amorphous silicon film 32 serving as a gate electrode are formed thereon. A hydrophobic treatment is performed on the semiconductor substrate 11 to be processed.
[0019]
Specifically, the nitrogen gas sent out from the vaporized gas introduction unit 3 is passed through a silica gel tube 4 to remove water, and hexamethyldisilazane in the HMDS bubbler 2 is vaporized using the water gas from which the water has been removed. Then, the vaporized hexamethyldisilazane is sprayed onto the surface of the semiconductor substrate 11 heated and maintained at 110 ° C. by the hot plate 12 in the closed chamber 1 for 20 seconds.
[0020]
Subsequently, as shown in FIG. 2B, a photoresist having a product name of PF1-34 (manufactured by Sumitomo Chemical Co., Ltd.) is applied to the surface of the amorphous silicon film 32 so as to have a thickness of about 1.18 μm. And developing, a resist pattern 33 is formed.
[0021]
Actually, when the resist pattern 33 was formed as described above, no resist pattern defect accompanied by a residue was confirmed.
[0022]
On the other hand, as shown in FIG. 3, using a substrate processing apparatus configured by removing the silica gel tube 4 as the water removing means from the apparatus configuration of FIG. When the surface of the semiconductor substrate on which the amorphous silicon film was formed was subjected to a hydrophobic treatment, a large number of resist pattern defects in which a residue was left in a portion where the resist did not normally remain were observed.
[0023]
Subsequently, as shown in FIG. 2C, the amorphous silicon film 32 and the thermal oxide film 31 are dry-etched using the resist pattern 33 as a mask to form the gate insulating film 22 and the gate electrode 23 according to the shape of the resist pattern 33. Form a pattern.
[0024]
Thereafter, the resist pattern 33 is removed by ashing or the like. Then, the source / drain 24 by ion implantation using the gate electrode 23 as a mask, an interlayer insulating film 25 covering the gate electrode 23, and a wiring layer formed on the interlayer insulating film 25 and electrically connected to the source / drain 24 via the contact hole 26 27 and the like are formed to complete a MOS transistor as shown in FIG.
[0025]
As described above, according to the present embodiment, unnecessary decomposition products are prevented from being generated at the time of the hydrophobic treatment, resist pattern defects are suppressed, and photolithography represented by the gate insulating film 22 and the gate electrode 23 is performed. The occurrence of defects in various patterns based on the above is reliably prevented. This makes it possible to realize a highly reliable MOS transistor with a high yield.
[0026]
-Variations of this embodiment-
Here, various modifications of the present embodiment will be described. These modified examples exemplify a method of manufacturing a MOS transistor as in the present embodiment, but differ in that the configuration of a substrate processing apparatus used for the hydrophobic treatment is partially different. Therefore, for convenience, in these modified examples, the configuration of the substrate processing apparatus and the hydrophobic treatment will be mainly described. Note that the same reference numerals are given to the same manufacturing processes, constituent members, and the like as in the above-described embodiment, and description thereof is omitted.
[0027]
[Modification 1]
As shown in FIG. 4, the substrate processing apparatus used in the present embodiment is configured such that the moisture in the nitrogen gas as a vaporizing gas is provided between the vaporized gas introducing unit 3 and the HMDS bubbler 2 instead of the silica gel tube 4 in FIG. And a refrigerator 41 for freezing and removing the same.
[0028]
Here, when the surface of the semiconductor substrate 11 on which the amorphous silicon film 32 is formed is subjected to the hydrophobic treatment, the nitrogen gas sent from the vaporized gas introduction unit 3 is passed through the refrigerator 41 to remove moisture, and the moisture is removed. Hexamethyldisilazane in the HMDS bubbler 2 is vaporized using the nitrogen gas that has been vaporized, and the vaporized hexamethyldisilazane is deposited on the surface of the semiconductor substrate 11 heated and maintained at 110 ° C. by the hot plate 12 in the closed chamber 1. Spray for 20 seconds.
[0029]
In this case, in the dehumidification of nitrogen gas, which is a gas for vaporizing hexamethyldisilazane, by the refrigerator 41, a dehumidifying effect can be obtained if the temperature is lower than -10 ° C, but a sufficient dehumidifying effect is lower than -20 ° C. Is more preferable for obtaining
[0030]
Further, as shown in FIG. 5, a heat exchanger 42 may be provided between the refrigerator 41 and the HMDS bubbler 2 as needed to return the nitrogen gas passed through the refrigerator 41 to normal temperature. .
[0031]
Subsequently, similarly to FIG. 2B, a photoresist having a product name of PF1-34 (manufactured by Sumitomo Chemical Co., Ltd.) is applied to the surface of the amorphous silicon film 32 to a film thickness of about 1.18 μm, By performing development, a resist pattern 33 is formed.
[0032]
Actually, when the resist pattern 33 was formed as described above, no resist pattern defect accompanied by a residue was confirmed.
[0033]
As described above, according to the first modification, unnecessary decomposition products are prevented from being generated during the hydrophobization treatment, resist pattern defects are suppressed, and photolithography represented by the gate insulating film 22 and the gate electrode 23 is performed. The occurrence of defects in various patterns based on the above is reliably prevented. This makes it possible to realize a highly reliable MOS transistor with a high yield.
[0034]
[Modification 2]
As shown in FIG. 6, the substrate processing apparatus used in this example has a function of sieving only water molecules between the vaporized gas introduction unit 3 and the HMDS bubbler 2 instead of the silica gel tube 4 of FIG. A molecular sieve 43 for removing moisture from the nitrogen gas is provided.
[0035]
Here, when the surface of the semiconductor substrate 11 on which the amorphous silicon film 32 is formed is subjected to the hydrophobic treatment, the nitrogen gas sent from the vaporized gas introduction unit 3 is passed through the molecular sieve 43 to remove moisture, and the moisture is removed. Hexamethyldisilazane in the HMDS bubbler 2 is vaporized using the nitrogen gas that has been vaporized, and the vaporized hexamethyldisilazane is deposited on the surface of the semiconductor substrate 11 heated and maintained at 110 ° C. by the hot plate 12 in the closed chamber 1. Spray for 20 seconds.
[0036]
Subsequently, similarly to FIG. 2B, a photoresist having a product name of PF1-34 (manufactured by Sumitomo Chemical Co., Ltd.) is applied to the surface of the amorphous silicon film 32 to a film thickness of about 1.18 μm, By performing development, a resist pattern 33 is formed.
[0037]
Actually, when the resist pattern 33 was formed as described above, no resist pattern defect accompanied by a residue was confirmed.
[0038]
As described above, according to the first modification, unnecessary decomposition products are prevented from being generated during the hydrophobization treatment, resist pattern defects are suppressed, and photolithography represented by the gate insulating film 22 and the gate electrode 23 is performed. The occurrence of defects in various patterns based on the above is reliably prevented. This makes it possible to realize a highly reliable MOS transistor with a high yield.
[0039]
In the above-described embodiment and its various modifications, nitrogen gas is used as a vaporizing gas used for vaporizing and introducing hexamethyldisilazane as a hydrophobizing agent. However, the present invention is not limited to nitrogen. , Neon, argon, or another inert gas may be used.
[0040]
In addition, although a novolak-based positive photoresist, product name PF1-34 (manufactured by Sumitomo Chemical Co., Ltd.) was used as the photoresist, other novolak-based positive photoresists, KrF resists, ArF resists, and the like are used. However, similar excellent effects can be obtained.
[0041]
Hereinafter, various aspects of the present invention will be collectively described as supplementary notes.
[0042]
(Supplementary Note 1) A chamber in which a substrate to be processed is installed;
Storage means for storing a liquid hydrophobizing agent,
Vaporizing means for introducing a vaporizing gas to the hydrophobizing agent in the storage means, and vaporizing the hydrophobizing agent,
A water removing unit disposed between the vaporizing unit and the storage unit, for removing water from the vaporizing gas sent from the vaporizing unit;
And a delivery unit for delivering the vaporized hydrophobizing agent to the substrate installed in the chamber.
[0043]
(Supplementary Note 2) The substrate processing apparatus according to Supplementary Note 1, wherein the hydrophobizing agent is hexamethyldisilazane.
[0044]
(Supplementary Note 3) The substrate processing apparatus according to Supplementary Note 1 or 2, wherein the moisture removing unit is any one of silica gel, molecular sieve, and a refrigerator.
[0045]
(Supplementary Note 4) a step of removing water from the vaporizing gas;
Introducing the vaporized gas from which water has been removed to a stored liquid hydrophobizing agent, and vaporizing the hydrophobizing agent;
Sending the vaporized hydrophobizing agent to a non-processed substrate and hydrophobizing the substrate surface.
[0046]
(Supplementary note 5) The substrate processing method according to supplementary note 4, wherein the hydrophobizing agent is hexamethyldisilazane.
[0047]
(Supplementary note 6) The substrate processing method according to Supplementary note 4 or 5, wherein any one of a silica gel, a molecular sieve, and a refrigerator is used in removing moisture from the vaporizing gas.
[0048]
(Supplementary Note 7) a step of forming a desired thin film on the surface of the semiconductor substrate;
Hydrophobizing the surface of the semiconductor substrate,
Applying a resist on the thin film, processing the resist to form a resist pattern, and then etching the thin film using the resist pattern as a mask,
The hydrophobic treatment step,
Removing water from the vaporizing gas;
Introducing the vaporized gas from which water has been removed to a stored liquid hydrophobizing agent, and vaporizing the hydrophobizing agent;
Sending the vaporized hydrophobizing agent to a non-processed substrate and hydrophobizing the surface of the semiconductor substrate.
[0049]
(Supplementary note 8) The method for manufacturing a semiconductor device according to supplementary note 7, wherein the hydrophobizing agent is hexamethyldisilazane.
[0050]
(Supplementary note 9) The method for producing a semiconductor device according to supplementary note 7 or 8, wherein any one of a silica gel, a molecular sieve, and a refrigerator is used in removing moisture from the vaporizing gas.
[0051]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, generation | occurrence | production of an unnecessary decomposition | disassembly product at the time of a hydrophobization process is prevented, the resist pattern defect is suppressed, and generation | occurrence | production of the defect of various patterns based on photolithography is reliably prevented. Thus, a highly reliable semiconductor device with a high yield can be realized.
[Brief description of the drawings]
FIG. 1 is a schematic diagram illustrating a schematic configuration of a substrate processing apparatus for performing substrate processing according to an embodiment.
FIG. 2 is a schematic cross-sectional view showing a method for manufacturing a semiconductor device in the present embodiment in the order of steps.
FIG. 3 is a schematic diagram showing a substrate processing apparatus configured as a comparative example except that a silica gel tube 4 serving as a water removing unit is removed from the apparatus configuration of FIG.
FIG. 4 is a schematic diagram illustrating a schematic configuration of a substrate processing apparatus for performing substrate processing according to a first modification.
FIG. 5 is a schematic diagram showing a schematic configuration of another substrate processing apparatus for performing substrate processing in Modification Example 1.
FIG. 6 is a schematic diagram illustrating a schematic configuration of a substrate processing apparatus for performing substrate processing according to a second modification.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Closed chamber 2 HMDS bubbler 3 Vaporization gas introduction part 4 Silica gel tube 5 Hydrophobic treatment agent sending part 11 Silicon semiconductor substrate 12 Hot plate 13 Solenoid valve 21 Field oxide film 22 Gate insulating film 23 Gate electrode 24 Source / drain 25 Interlayer insulation Film 26 contact hole 27 wiring layer 31 thermal oxide film 32 amorphous silicon film 33 resist pattern 41 refrigerator 42 heat exchanger 43 molecular sieve

Claims (5)

A chamber in which a substrate to be processed is installed;
Storage means for storing a liquid hydrophobizing agent,
Vaporizing means for introducing a vaporizing gas to the hydrophobizing agent in the storage means, and vaporizing the hydrophobizing agent,
A water removing unit disposed between the vaporizing unit and the storage unit, for removing water from the vaporizing gas sent from the vaporizing unit;
And a delivery unit for delivering the vaporized hydrophobizing agent to the substrate installed in the chamber. 2. The substrate processing apparatus according to claim 1, wherein the hydrophobizing agent is hexamethyldisilazane. The substrate processing apparatus according to claim 1, wherein the water removing unit is any one of silica gel, molecular sieve, and a refrigerator. Removing water from the vaporizing gas;
Introducing the vaporized gas from which water has been removed to a stored liquid hydrophobizing agent, and vaporizing the hydrophobizing agent;
Sending the vaporized hydrophobizing agent to a non-processed substrate and hydrophobizing the substrate surface. Forming a desired thin film on the surface of the semiconductor substrate;
Hydrophobizing the surface of the semiconductor substrate,
Applying a resist on the thin film, processing the resist to form a resist pattern, and then etching the thin film using the resist pattern as a mask,
The hydrophobic treatment step,
Removing water from the vaporizing gas;
Introducing the vaporized gas from which water has been removed to a stored liquid hydrophobizing agent, and vaporizing the hydrophobizing agent;
Sending the vaporized hydrophobizing agent to a non-processed substrate and hydrophobizing the surface of the semiconductor substrate.

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