JP3761951B2 - Ferroelectric thin film forming equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention, by directing a ferroelectric material mist state onto a substrate, to a Ru is deposited ferroelectric thin film ferroelectric thin film forming apparatus.
[0002]
[Prior art]
Current developments in ferroelectric materials include both development of DRAM capacitors as high dielectric constant materials and development of nonvolatile memories that utilize applied voltage and hysteresis characteristics of dielectric polarization. Ferroelectric thin film materials that are most researched and developed for application to semiconductor devices include BST films mainly composed of barium, strontium, and titanium, and Y1, which is a bismuth-based layered compound. In addition, there is a sol-gel method such as sputtering or spin coating as a method for forming a ferroelectric material, and in recent years, a volatile solution containing a ferroelectric material is misted and used as a carrier gas. There is a ferroelectric thin film forming apparatus which is carried on the silicon substrate and is deposited on a silicon substrate.
[0003]
A conventional ferroelectric thin film forming apparatus will be described below. FIG. 2 is a simple schematic diagram showing the configuration of a conventional ferroelectric thin film forming apparatus.
In FIG. 2, 16 is a process chamber for forming a ferroelectric thin film, 11 is an atomizer (mist generator) that mists a volatile solution containing a ferroelectric material by an ultrasonic oscillator, and 12 is misted. This is a carrier gas pipe for guiding the ferroelectric material from the atomizer 11 to the process chamber 16. In the process chamber 16, there are provided a substrate stage 15 on which a silicon substrate is placed, an upper plate 14 and a vacuum evacuation pipe 13 disposed above the substrate stage 15 at predetermined intervals.
[0004]
Next, the ferroelectric thin film is formed as follows. The ferroelectric material misted by the atomizer 11 is introduced into the process chamber 16 under reduced pressure through the carrier gas pipe 12 along the flow of the carrier gas. The mist discharged from the discharge port 17 at the front end of the carrier gas pipe is diffused along the flow of evacuation, and a part of the mist is led to the gap between the rotating substrate stage 15 and the upper plate 14 to form a laminar flow therethrough. A ferroelectric thin film is deposited on the substrate.
[0005]
[Problems to be solved by the invention]
However, in the above-described conventional configuration, the mist discharged from the discharge port 17 diffuses in all directions, and the mist guided to the gap between the substrate stage 15 and the upper plate 14 becomes a part of the entire mist, so the film formation rate is high. The maintenance frequency is high because it is low and the diffused mist adheres to the inner wall of the process chamber.
[0006]
The present invention is intended to solve the conventional problems described above, the strength increases the deposition rate of the dielectric thin film, and an object thereof is to provide a ferroelectric thin film forming apparatus suppressing the maintenance frequency.
[0008]
[Means for Solving the Problems]
The method for forming a ferroelectric thin film of the present invention includes a process chamber, a vacuum drawing pipe provided in the process chamber, a substrate stage provided in the process chamber, and a substrate stage provided in the process chamber so as to face the substrate stage . a smaller top plate from the substrate stage, and the mist generator for mist of a solution containing a ferroelectric material, provided vacuum pipe and the counter, and the upper plate mist be mist substrate stage mist generator A carrier gas pipe provided above the substrate stage for discharging between the substrate stage and the carrier gas pipe in the process chamber and obliquely above the periphery of the gap between the substrate stage and the upper plate. The flow of mist is controlled to prevent mist from diffusing in all directions, and it is efficient on the substrate Is obtained by a control gas pipe ejected from obliquely upward with respect to the substrate stage control gas for induction.
[0009]
According to the ferroelectric thin film forming apparatus of the present invention , the mist discharged from the carrier gas pipe has a control gas that acts as a barrier against diffusion that is jetted from the control gas pipe, so that diffusion is minimized. Further, by adjusting the direction and flow rate of the control gas, the mist can be guided and deposited on the substrate most efficiently.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Ferroelectric thin film forming apparatus that put to an embodiment of the present invention will be described. FIG. 1 shows a cross-sectional view of a process chamber of a ferroelectric thin film forming apparatus. In FIG. 1, 1 is an atomizer (mist generator), 2 is a newly installed control gas pipe for controlling the flow of carrier gas, 3 is a carrier gas pipe, 4 is a vacuuming pipe, 5 is an upper plate, and 6 is a substrate stage. , 7 is a process chamber.
[0011]
In the apparatus of this embodiment, due to the configuration of the apparatus, the control gas pipe 2 is provided above the carrier gas pipe 3 and the outlet 9 of the control gas pipe 2 having the same shape as the discharge port 8 of the carrier gas pipe 3 is provided. Is directed slightly above the gap between the substrate stage 6 and the upper plate 5. Further, using the common argon as the carrier gas and the control gas, set the control gas flow rate and the carrier gas flow rate to the same 200 sccm, high as 2 kg / cm ³ for control gas pressure to the carrier gas pressure 1 kg / cm ³ Set to value.
[0012]
Next, a ferroelectric thin film forming method using the ferroelectric thin film forming apparatus of FIG. 1 will be described. The misted ferroelectric material is introduced into the process chamber 7 through the carrier gas pipe 3 in the same manner as in the prior art. Although the mist discharged from the discharge port 8 of the carrier gas pipe 3 is supposed to be diffused in all directions, it is affected by the flow of high-pressure gas discharged from the control gas pipe 2 installed above. That is, the control gas acts as a barrier against upward diffusion, and the mist is transferred to the substrate stage by adjusting the control gas piping installation position, the surface direction of the jet port 9, the gas flow rate, and the gas pressure. 6 and lead to the gap between the upper plate 5. In this way, a ferroelectric thin film is formed on the silicon substrate placed on the substrate stage 6.
[0013]
According to such a ferroelectric thin film forming apparatus thus configured, by which established the control gas pipe 2, to suppress the diffusion of the mist increases the proportion of the mist to deposit on the substrate, the ferroelectric film forming the thin film The rate is improved. In addition, since the amount of mist adhering to the inner wall of the process chamber can be minimized, this apparatus can reduce the maintenance frequency and increase the throughput as compared with the conventional apparatus.
[0014]
In the above embodiment, the control gas pipe 2 is installed above the carrier gas pipe 3 and the gas type, gas flow rate and gas pressure are set as described above. However, the present invention is limited to such a configuration. However, it is only necessary to determine according to the configuration of the apparatus, and the same effect can be obtained.
[0015]
【The invention's effect】
According to the ferroelectric thin film forming apparatus of the present invention , the mist discharged from the carrier gas pipe has the control gas that acts as a counter-diffusion barrier ejected from the control gas pipe, so that the diffusion can be minimized. Further, by adjusting the direction and flow rate of the control gas, the mist can be guided and deposited on the substrate with the highest efficiency. As a result, the deposition rate of the ferroelectric thin film can be improved, and the amount of mist adhering to the inner wall of the process chamber can be minimized and the maintenance frequency can be kept low. .
[Brief description of the drawings]
FIG. 1 is a schematic diagram of a ferroelectric thin film forming apparatus according to an embodiment of the present invention.
FIG. 2 is a schematic view of a conventional ferroelectric thin film forming apparatus.
[Explanation of symbols]
1 Atomizer (mist generator)
2 Control gas piping 3 Carrier gas piping 4 Vacuum drawing piping 5 Upper plate 6 Substrate stage 7 Process chamber 8 Discharge port 9 Spout port

Claims (1)

A process chamber;
And vacuum piping provided in said process chamber,
A substrate stage provided in the process chamber;
In the process chamber, an upper plate smaller than the substrate stage provided facing the substrate stage,
A mist generator for misting a solution containing a ferroelectric material;
The evacuation pipe opposite to provided the mist for discharging the mist is mist between the upper plate and the substrate stage generator, a carrier gas pipe provided above said substrate stage When,
It is provided above the carrier gas pipe in the process chamber and obliquely above the periphery of the gap between the substrate stage and the upper plate, and the mist diffuses in all directions by controlling the flow of the mist. A ferroelectric thin film forming apparatus , comprising: a control gas pipe for controlling and efficiently ejecting a control gas on the substrate from obliquely above the substrate stage .

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