KR20040001368A - The method of PBN film forming by CVD - Google Patents

Abstract

PURPOSE: A method of forming PBN(Pyrolitic Boron Nitride) film by using the CVD(Chemical Vapor Deposition) is provided to define the range of reaction gas charge ratio, reaction temperature and reaction pressure of a carrier gas, which is enough for producing the PBN film, by an experiment. CONSTITUTION: In producing a PBN film in a CVD reaction chamber, BCl3, B2H6 or NH3 gas is used as the main reaction gas, and N2 or H2 gas is used as the carrier gas. In the process of producing the PBN film, the reaction temperature is set to 700 °C-2300 °C, and the reaction pressure of the carrier gas is set to 0.01 torr-20 torr.

Description

PBN thin film manufacturing method by vapor deposition {The method of PBN film forming by CVD}

The present invention relates to a method of manufacturing PBN (Pyrolitic Boron Nitride) coated film (PBN) having excellent chemical resistance and thermal conductivity and excellent insulation by reacting BCl ₃ or B ₂ H ₆ gas with NH ₃ gas at high temperature and low pressure. At this time, N ₂ or H ₂ Gas may be used as the carrier gas.

As the integration of semiconductor devices increases toward the future, the proportion of single-wafer type in the pre-processing equipment increases and the wafer size is also large from 200mm to 300mm. Is going on.

In particular, the conventional method in terms of the chuck function of the susceptor that supports the wafer when manufacturing the wafer is a simple mechanical contact method, which is a clamp type. Recently, many researches have been focused on the ESC (ElectroStaticChuck) method, which is a non-contact method, and this ESC method necessarily requires a thin film of insulating material on the conductor to induce static electricity. One of the excellent insulating thin films that meets this demand is PBN (Pyrolitic Boron Nitride).

In particular, since the wafer manufacturing process consists of many processes such as heating, cooling, gas injection, and plasma use, the susceptor supporting the wafer should have excellent heat transfer, excellent chemical resistance, and excellent insulation for preventing electrical shorts and inducing static electricity of the wafer. This is necessary. PBN has excellent heat transfer, chemical resistance, high mechanical strength, and high insulation, making it a very good material for the manufacture of heaters without the risk of suceptors or electrical shorts.

However, PBN thin film manufacturing method has a lot of current shortage of thin film formation technology by vapor deposition method to be used industrially, not academic.

Therefore, the present invention relates to the production of industrially useful PBN thin film can be usefully applied to the manufacturing industry of various fields.

An object of the present invention is BCl ₃ or B ₂ H ₆ gas as a thin film formation technology that can satisfy these properties when the surface of carbon, ceramics, metals, etc. is excellent in heat transfer and high mechanical strength, chemical resistance, insulation, etc. are required And a method of manufacturing PBN (Pyrolitic Boron Nitride) coated film having excellent chemical resistance, thermal conductivity and excellent insulation by reacting NH ₃ gas at high temperature and low pressure. In this case, N ₂ or H ₂ Gas is used as carrier gas. These gases can also be used to specify the reaction gas input ratio, reaction temperature, reaction pressure, etc. that can form PBN thin film through experiments.

Figure 1 is a schematic diagram of a CVD apparatus capable of forming a PBN thin film.

Pic 1

NH ₃ (99.9995%) gas was introduced into the chamber through 316 Stainless Steel, and BCl ₃ (99.999%) or B ₂ H ₆ (99.999%) gas and N ₂ (99.999%) or H ₂ (99.999%) gas It is designed to be fed through 1 identical 316 stainless steel just before loading.

Gas flow rate can be adjusted by Mass Flow Controller (MFC), and the flow rate of BCl ₃ and NH ₃ is 15-1000SCCM (Standard Cubic Centimetre per Minute), N ₂ or H ₂ is used more than 150SCCM. Could be changed.

The total gas pressure in the reaction chamber was automatically maintained at a constant pressure during the reaction by a pressure control valve attached to the outlet. The experimental reaction gas voltage range was 0.01-20torr.

Filter and heat is made to use the temperature inside the reaction chamber is made to experiments while changing 700-2300 ℃ blocking NH ₄ Cl and harmful gas generated after the desired temperature was to be automatically adjusted, while keeping the reaction experiment Graphite Heater The wet scrubber was mounted before and after the vacuum pump. In order to maintain the degree of vacuum at the joints, a coolant flow system is also installed to prevent overheating.

The present invention will be described in detail with reference to the following specific examples, but the scope of the present invention is not limited thereto.

Example 1.

Graphite discs with a density of 1.75 g / cm ² (diameter: 3 cm, thickness: 1 cm) are washed with alcohol and acetone and blown with nitrogen gas to dry completely. Put the washed object deposited in the reaction chamber by using the ZIG If no abnormality is found by the Leak Check in a state in which the temperature was raised up to a vacuum, while maintaining (or less 0.01torr) 700 ℃ per minute to 10 ℃ and maintain a 700 ℃ N ₂ gas Open the valve and inject it at 100cm ² / min, and keep the reaction chamber pressure at 5torr by automatic control. Subsequently, the reaction was carried out by allowing NH ₃ to 60 cm ² / min and BCl ₃ to be injected at a constant flow for 2 hours at 90 cm ² / min.

After the reaction for 2 hours (if you want to keep the reaction, keep this condition for the desired time) Lock the gas line in the order of BCl ₃ , NH ₃ , N ₂ , and keep the chamber internal pressure below 0.01torr, Get off. When the temperature is below 100 ° C, the specimen is removed by using N ₂ gas to make the pressure in the chamber equal to atmospheric pressure.

The deposited specimen is a white BN thin film, and the deposition rate is inversely proportional to the distance of the specimen in the reaction gas mixing region, and the deposition rate is less than 12um / hr.

Example 2.

Even if the reaction temperature was set at 1500 ° C., the same procedure as in Example 1 was carried out to obtain a BN thin film. The same method as in Example 1 was followed, but the reaction temperature was only 800 ° C., 900 ° C., 1000 ° C., 1100 ° C., 1100 ° C., 1200 BN thin films are also obtained when the temperature is different from 1 ° C, 1300 ° C, 1400 ° C, 1600 ° C, 1700 ° C, 1800 ° C, 1900 ° C, 2000 ° C, 2100 ° C, 2200 ° C and 2300 ° C.

Example 3.

The same BN thin film can be obtained even if the same conditions and reaction pressure as in Example 1 are changed to 0.01 to 20 torr. At this time, the hourly volume of NH ₃ and BCl ₃ may be changed in order to control the desired reaction pressure.

Example 4.

Example 1. N ₂ gas instead of the same one can achieve the same effect also with the H ₂ gas and the amount used is N _2, H ₂ gas is preferably one or both the secondary gas, which is used for more than twice the BCl ₃ gas is used as the Carrier Gas I didn't have to use

Example 5.

As in Example 1, BN thin films could be obtained by changing the volume ratio of NH ₃ and BCl ₃ , but [NH ₃ ] / [BCl ₃ ] = 1.5 was the best in terms of BN thin film yield.

The characteristics of the PBN thin film deposited by the above method are shown in Table 1.

Table 1.

Component analysis showed that BN was over 99% and impurities such as B ₂ O ₃ were less than 1%.

Materials that have excellent heat transfer but also have insulation, high mechanical strength, chemical resistance, and non-pollution properties can be effectively applied in various fields. PBN thin films have this property at the same time.

For example, in the manufacture of semiconductor wafers, the susceptor not only supports the wafers functionally but also requires excellent heat transfer, high mechanical strength, especially high insulation and chemical resistance.

Because of this property, it is a good susceptor that satisfies all conditions at once if it replaces the existing susceptor with PBN thin film coated on Graphite.

In addition, it can be used to manufacture ESC (Electrostatic Chuck) using high insulation of PBN thin film, and can be used to manufacture Heater which has no risk of electric short or short circuit.

Claims (2)

PBN (Pyrolitic Boron Nitride) coated film (CVD) can be prepared by CVD (vapor deposition) reaction using BCl ₃ or B ₂ H ₆ gas and NH ₃ gas as the main reaction gas as N ₂ or H ₂ gas as the carrier gas. When the reaction temperature is 700 ℃ ~ 2300 ℃ The reaction pressure of claim 1 is 0.01torr ~ 20torr