JP3773458B2 - Substrate processing method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a substrate processing method and apparatus for performing a predetermined process on a glass substrate (hereinafter simply referred to as a substrate) for a semiconductor wafer or a liquid crystal display device, and in particular, a film material containing a high dielectric constant material is deposited. TECHNICAL FIELD OF THE INVENTION
[0002]
[Prior art]
In the semiconductor field in recent years, LSIs having many functions have been developed by miniaturization of elements such as transistors. Therefore, the operation speed of the circuit has been increased, but in the process, the reduction in the thickness of the gate oxide insulating film is reaching its limit. In other words, an increase in leakage current accompanying the reduction in thickness is a big problem.
[0003]
Therefore, in order to solve this problem, high dielectric constant materials have attracted attention as a new material that has a high dielectric constant and can suppress leakage current, instead of the oxide film that has been used for the gate insulating film. Yes.
[0004]
[Problems to be solved by the invention]
However, the conventional example having such a configuration has the following problems.
That is, as a material having a high dielectric constant and usable in the semiconductor field, there are metal oxides such as aluminum and hafnium. However, these cannot be processed with conventionally used processing solutions for etching and cleaning. There is a problem. Therefore, despite the investigation of promising high dielectric constant materials that replace conventional materials, their use has not been promoted.
[0005]
This invention is made | formed in view of such a situation, Comprising: It aims at providing the substrate processing method and apparatus which can process the board | substrate using a high dielectric constant material suitably.
[0006]
[Means for Solving the Problems]
The present inventors have obtained the following knowledge in order to solve the above problems.
That is, as a result of various experiments conducted under the condition that the high dielectric constant material can be selectively treated and the substrate is not contaminated by the treatment, a treatment liquid containing sulfuric acid is obtained. It was found that the above-mentioned conditions are satisfied by heating. The present invention based on such knowledge is configured as follows.
[0007]
That is, in the invention described in claim 1, the treatment liquid containing sulfuric acid is heated in a range of 150 to 180 ° C., and the treatment liquid contains an oxide containing any one of aluminum Al, hafnium Hf, and zirconium Zr, or The substrate is treated with a film material including a high dielectric constant material which is silicate or aluminate .
[0008]
(Operation and Effect) The present inventors have, as a result of experiment for processing the high dielectric constant material by the treatment liquid by heating the treating solution containing sulfuric acid, and the heated, from around exceeding a certain temperature, aluminum Al, hafnium It has been found that high dielectric constant materials that are oxides or silicates or aluminates containing any one of Hf and zirconium Zr can be processed. Therefore, it is confirmed that the high dielectric constant material can be selectively treated by processing the high dielectric constant material using the treatment liquid heated in the range of 150 to 180 ° C., and the substrate is not contaminated. did. Thus, the board | substrate using a high dielectric constant material can be processed suitably by using for a process, after heating the process liquid containing a sulfuric acid in the range of 150-180 degreeC.
[0009]
Specifically, Al ₂ O ₃ , HfSi _x O _y , HfO ₂ , HfSi _x O _y , ZrAl _x O _y , ZrO _{2 and the} like are exemplified.
[0010]
Moreover, it is preferable that the sulfuric acid concentration in said process liquid exists in the range of 20-100 weight% by various experiment (Claim 2).
[0011]
(Delete)
[0012]
(Delete)
[0013]
In order to carry out the substrate processing method described above, as described in claim 3 , an oxide, silicate, or aluminate containing any one of aluminum Al, hafnium Hf, and zirconium Zr is used. In a substrate processing apparatus for processing a substrate coated with a film material including a dielectric constant material, a processing tank for storing the substrate and performing processing, and a processing liquid pipe for supplying a processing liquid containing sulfuric acid to the processing tank And a heating means for heating the treatment liquid in a range of 150 to 180 ° C.
[0014]
(Operation / Effect) The treatment tank is supplied with a treatment solution containing sulfuric acid through a treatment solution pipe, and the treatment solution is heated in the range of 150 to 180 ° C. by a heating means to obtain aluminum Al, hafnium. A substrate coated with a high dielectric constant material that is an oxide, silicate, or aluminate containing any one of Hf and zirconium Zr can be suitably processed.
[0015]
Moreover, it is preferable that the said heating means is arrange | positioned in the said process liquid piping as described in Claim 5 .
[0016]
(Operation / Effect) In order to heat the treatment liquid containing sulfuric acid, a heating means is provided in the treatment liquid pipe, and the treatment liquid flowing through the treatment liquid pipe is heated. Thereby, it can heat efficiently compared with the system which heats the processing liquid stored in the processing tank.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described below with reference to the drawings.
<Substrate processing method>
FIG. 1 is a graph showing experimental results by the method of the present invention.
This graph is a graph of the etching rate as a result of an experiment in which a substrate coated with a film material containing a high dielectric constant material is etched. For the etching process, a processing solution containing sulfuric acid was used, and the etching rate was measured for each temperature while changing the heating temperature of the processing solution.
[0018]
Specific heating temperatures are 23 ° C., 150 ° C., 160 ° C., 170 ° C., and 180 ° C. The upper limit of the heating temperature is 180 ° C. due to the heating limit in the experimental apparatus.
[0019]
The sulfuric acid concentration in the treatment liquid in the experiment is 96% by weight, but the same effect is obtained if it is in the range of 20 to 100% by weight. If the sulfuric acid concentration is less than 20% by weight, the etching rate becomes too slow and falls outside the practical range.
[0020]
Samples include those using the organic metal source chemical vapor deposition (MO CVD) method and those using the atomic layer chemical vapor deposition (AL CVD) method for depositing a high dielectric constant material. is there. Zirconium Zr and hafnium Hf were used as the high dielectric constant material. Specifically, the ZrO ₂ by MO CVD method, and ZrO ₂ by AL CVD method is a HfO ₂ and HfSiO _x by MO CVD method.
[0021]
In addition, as a comparison target of the above-described high dielectric constant materials, three types were used: a conventionally used thermal oxide film, an amorphous silicon P-implanted material, and amorphous silicon.
[0022]
As is apparent from the graph of FIG. 1, when the treatment liquid containing sulfuric acid is heated, etching of high dielectric constant materials (groups indicated by high-k in the figure) starts at around 100 ° C. and further above 150 ° C. You can see that the rate is higher. On the other hand, it can be seen that the etching rate of the conventional material (the group indicated by Ref. In the figure) is not as high as that of the high dielectric constant material even when the treatment liquid is heated.
[0023]
In other words, when a high dielectric constant material is used as the gate insulating oxide film, it shows that the effect of the processing liquid is extremely small compared to the conventional material used for the substrate, and the selective processing by the processing liquid is performed. Indicates that it is possible. Further, since the treatment liquid contains sulfuric acid, organic substances and the like can be completely removed, and the substrate is not contaminated by the high dielectric constant material melting out.
[0024]
From the above experimental results, it can be seen that the etching rate is appropriate and within the practical range when the heating temperature of the treatment liquid is in the range of about 100 to 200 ° C. Accordingly, the treatment liquid containing sulfuric acid in the range of 20 to 100% by weight is heated in the range of 100 to 200 ° C., preferably in the range of 150 to 180 ° C., to treat the substrate on which the film material containing the high dielectric material is deposited. When used, processing can be suitably performed.
[0025]
Next, a specific example of processing by the substrate processing method described above will be briefly described with reference to FIG. FIG. 2 is a diagram for explaining specific processing by the method of the present invention. FIG. 2 (a) shows before etching, FIG. 2 (b) shows after dry etching, and FIG. 2 (c). Indicates after etching with the treatment liquid.
[0026]
In the substrate W, a high dielectric constant material (High-k) HK and Poly-Si and PSG as gate electrodes are already formed on top of Si. Further, a mask (resist) M is selectively formed on the upper portion. Since the treatment liquid contains sulfuric acid, the mask M is preferably a material containing Poly-Si, SiO ₂ , SiN having resistance to sulfuric acid.
[0027]
As shown in FIG. 2A, the substrate W on which the mask M is formed is dry-etched. As a result, as shown in FIG. 2B, the PSG in the portion not covered with the mask M is etched, and the high dielectric constant material (High-k) HK is dry-etched halfway in the thickness direction. .
[0028]
Finally, the substrate W after dry etching is immersed in a processing solution heated to the above range. Thereby, as shown in FIG. 2C, the remaining high dielectric constant material (High-k) HK is etched away by the treatment liquid.
[0029]
<Substrate processing equipment>
Next, a substrate processing apparatus capable of suitably implementing the above-described substrate processing method will be described with reference to FIG. FIG. 3 is a diagram illustrating a schematic configuration of the substrate processing apparatus according to the embodiment.
[0030]
The substrate processing apparatus includes a holding arm 11, a processing tank 13, and a processing liquid pipe 15. The holding arm 11 holds a plurality of substrates W for processing, and is configured to be able to move up and down between the processing tank 13 and the immersion position (processing position) shown in FIG. The processing tank 13 includes an injection tube 17 for injecting a processing liquid at the bottom thereof. A recovery tank 19 for recovering and discharging the overflowing processing liquid is provided around the upper part. A processing liquid pipe 15 is connected to the injection pipe 17 in communication.
[0031]
The treatment liquid pipe 15 includes a filter 21, a heater 23 corresponding to the heating means in the present invention, a first supply pipe 25, and a second supply pipe 27. The filter 21 removes particles and the like in the processing liquid, and the heater 23 adjusts the temperature of the processing liquid to a predetermined temperature. The first supply pipe 25 is provided with a pure water supply source 29, and a control valve 31 for controlling the flow rate and opening / closing thereof is attached. A treatment liquid supply source 33 is provided in the second supply pipe 27, and a control valve 35 for controlling the flow rate and opening / closing thereof is attached. Note that the processing liquid stored in the processing liquid supply source 33 has already been adjusted to have the sulfuric acid concentration.
[0032]
The control unit 37 controls the flow rate as well as opening and closing the control valves 31 and 35. Moreover, the control part 37 controls the heater 23, and heats the process liquid which flows through the process liquid piping 15 to the said heating temperature. Moreover, the control part 37 controls the control valves 31 and 35 as needed, and adjusts the density | concentration of a process liquid.
[0033]
In the substrate processing apparatus configured as described above, the control unit 37 opens the control valve 35 and supplies a processing liquid having a predetermined concentration to the processing liquid pipe 15. The processing liquid supplied to the processing liquid pipe 15 is heated to a predetermined temperature by the heater 23 and then supplied to the processing tank 13. After the processing liquid fills the processing tank 13 and overflows into the recovery tank 19, the holding arm 11 waiting above the processing tank 13 is lowered to the immersion position shown in FIG. 3 while holding the substrate W. After a predetermined time has elapsed, the control unit 37 closes the control valve 35 and opens the control valve 31 to supply pure water to the treatment tank 13. As a result, the processing for the substrate W is stopped and the pure water cleaning processing is performed.
[0034]
According to the substrate processing apparatus configured as described above, the above-described substrate processing method can be preferably performed, and the substrate W on which the film material including the high dielectric material is deposited can be preferably processed.
[0035]
<First Modification>
Next, a modified example of the substrate processing apparatus will be described with reference to FIG.
In addition, about the thing of the same structure as the substrate processing apparatus mentioned above, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.
[0036]
In the substrate processing apparatus, the processing liquid overflowing from the processing tank 13 to the recovery tank 19 is discharged. In the apparatus shown in this modification, the processing liquid overflowing the recovery tank 19 is circulated. .
[0037]
Specifically, the treatment liquid pipe 15 </ b> A is connected in communication with the injection pipe 17 and the recovery tank 19. A control valve 39, a mixing unit 41, and a pump 43 are further provided in the processing liquid pipe 15A. The control valve 39 controls the flow and flow rate of the processing liquid pipe 15 </ b> A under the control of the control unit 37. The mixing unit 41 injects pure water from the pure water supply source 29 and treatment liquid from the treatment liquid supply source 33 into the treatment liquid pipe 15A. The pump 43 circulates the processing liquid and pure water in the processing liquid piping 15A.
[0038]
Even the substrate processing apparatus having the configuration shown in the first modification can obtain the same effects as those of the substrate processing apparatus described above.
[0039]
<Second Modification>
Next, another modification of the substrate processing apparatus will be described with reference to FIG.
The same components as those in the above apparatus are denoted by the same reference numerals, and detailed description thereof is omitted.
[0040]
In this apparatus, a heater is not provided in the processing liquid pipe 15A, and a heater 45 is provided in a recovery tank 19A having a larger storage amount than the above apparatus. Therefore, the processing liquid overflowing in the recovery tank 19A is heated by the heater 45 and is controlled by the control unit 37 so as to be within the above heating range. The heated processing liquid is circulated through the processing liquid pipe 15A by the pump 43 and circulates between the processing tank 13 and the recovery tank 19A.
[0041]
The device configured as described above can achieve the same effect as the above device. In addition, although the heating efficiency is lower than that of the above-described apparatus, there is an advantage that the configuration of the processing liquid pipe 15A can be simplified.
[0042]
The above-described apparatus has been described by taking as an example a batch process for collectively processing a plurality of substrates W, but the present invention can also be applied to a single wafer type.
[0043]
【The invention's effect】
As is clear from the above description, according to the present invention, any one of aluminum Al, hafnium Hf, and zirconium Zr is used by heating the treatment liquid containing sulfuric acid in the range of 150 to 180 ° C. A substrate using a high dielectric constant material which is an oxide, silicate, or aluminate containing one can be suitably processed.
[Brief description of the drawings]
FIG. 1 is a graph showing experimental results according to the method of the present invention.
FIGS. 2A and 2B are diagrams for explaining specific processing by the method of the present invention, in which FIG. 2A shows before etching, FIG. 2B shows after dry etching, and FIG. 2C shows after etching with a processing solution; .
FIG. 3 is a diagram illustrating a schematic configuration of a substrate processing apparatus according to an embodiment.
FIG. 4 is a view showing a first modification of the substrate processing apparatus.
FIG. 5 is a view showing a second modification of the substrate processing apparatus.
[Explanation of symbols]
W ... Substrate Si ... Silicon HK ... Film material containing high dielectric constant material (High-k) M ... Mask 13 ... Treatment tank 15 ... Treatment liquid piping 19 ... Recovery tank 23 ... Heater (heating means)
DESCRIPTION OF SYMBOLS 29 ... Pure water supply source 31 ... Control valve 33 ... Treatment liquid supply source 35 ... Control valve 37 ... Control part

Claims (5)

A treatment liquid containing sulfuric acid is heated in a range of 150 to 180 ° C., and this treatment liquid is an oxide, silicate, or aluminate containing any one of aluminum Al, hafnium Hf, and zirconium Zr. A substrate processing method, comprising: processing a substrate on which a film material including a refractive index material is deposited. The substrate processing method according to claim 1,
The substrate treatment method, wherein the treatment liquid has a sulfuric acid concentration of 20 to 100% by weight. In a substrate processing apparatus for processing a substrate on which a film material containing a high dielectric constant material which is an oxide, silicate or aluminate containing any one of aluminum Al, hafnium Hf, and zirconium Zr is applied.
A processing tank for accommodating and processing the substrate;
A treatment liquid pipe for supplying a treatment liquid containing sulfuric acid to the treatment tank;
A heating means for heating the treatment liquid in a range of 150 to 180 ° C . ;
A substrate processing apparatus comprising: The substrate processing apparatus according to claim 3 ,
The substrate processing apparatus, wherein the processing liquid has a sulfuric acid concentration of 20 to 100% by weight. The substrate processing apparatus according to claim 3 or 4 ,
The substrate processing apparatus, wherein the heating means is disposed in the processing liquid pipe.

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