JP3318595B2 - Laser ion plating equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for forming a thin film on a sample substrate, and further uses a laser beam to evaporate an evaporation sample made of a conductive solid material such as a metal or semiconductor. The present invention relates to an ion plating apparatus for forming a hard thin film of a compound composed of a sample for evaporation and a reaction gas on the sample.

[0002]

2. Description of the Related Art In a vapor deposition apparatus using a vacuum arc discharge shown in FIG. 3, by introducing a reaction gas into a vacuum chamber, a compound thin film composed of a sample for evaporation and components of the reaction gas can be formed at a high speed. Are known. That is, high-current vacuum arc discharge is applied between the cathode composed of the evaporating sample 4 and the anode 8 installed near the cathode, thereby giving high-density energy to the evaporating sample and rapidly heating it to evaporate the evaporating sample at high speed. At the same time, the vaporized particles and the reaction gas are ionized with high efficiency by high-density discharge, whereby a compound thin film composed of the sample for evaporation and the components of the reaction gas is formed on the sample substrate 17 at high speed. For example, using a Ti evaporation sample and a N ₂ reaction gas, the pressure is 0.8 to 5 Pa and the arc current is 50.
TiN is formed under the conditions of １００100 A.

FIG. 4 shows a vacuum deposition apparatus using a laser beam (Japanese Patent Application Laid-Open No. 3-1044862). The evaporation sample 4 and the thermoelectrons are emitted by condensing and irradiating the laser beam 11 to the evaporation sample 4 to which the negative voltage is applied, which is installed in the vacuum chamber 1, and the discharge current is reduced by the action of the two media. A stable vacuum arc discharge can be obtained even at a low current of 1 A. Compared to the apparatus shown in FIG. 3, this apparatus is characterized in that generation of droplets of a sample for evaporation called droplets is suppressed and a uniform thin film is obtained. That is, droplets are generated by overheating of the evaporation sample. However, in the apparatus shown in FIG. 3, it is impossible to reduce a high discharge current in order to maintain vacuum arc discharge, and it is not possible to avoid overheating. On the other hand, in the apparatus shown in FIG. 4, since the discharge current can be reduced, overheating can be suppressed and the generation of droplets can be avoided.

Further, the method shown in FIG. 3 has a problem that the discharge stops when an electrically insulating compound thin film is formed. That is, since a part of the ions of the reaction gas generated by the arc discharge is drawn into the cathode electrode, an insulating layer of the compound is formed on the surface of the cathode electrode, the bias effect is lost, and the discharge stops. In order to solve this problem, the apparatus shown in FIG. 4 has a feature that a stable discharge can be maintained because the insulating layer formed on the evaporation sample corresponding to the cathode electrode is evaporated and destroyed by the laser beam. .

[0005]

In the apparatus shown in FIG. 4, when a reaction gas is supplied to form a compound thin film, if the supply amount of the reaction gas is small, the reaction between the vaporized particles from the evaporation sample and the reaction gas is sufficient. Instead, a thin film mainly composed of the components of the evaporation sample is formed. On the other hand, if the reaction gas pressure is increased by increasing the supply amount of the reaction gas, the plasma density of the discharge is increased and the activation of the evaporated particles and the reaction gas is promoted. There is a problem that the adhesion to the sample substrate is reduced.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a laser ion plating apparatus capable of obtaining a compound thin film having high hardness and uniformity and high adhesion.

[0007]

SUMMARY OF THE INVENTION The present invention for this purpose has the following contents. (1) While introducing the reaction gas into the vacuum chamber,
The laser light is focused and irradiated to the evaporation sample a negative voltage is applied, it is arranged opposite to the evaporation sample, and a vaporization sample material and the reaction gas material to the sample substrate a negative bias voltage is applied in the laser ion plating apparatus for forming a compound thin film, the vacuum reaction gas supply passage provided within the chamber, gas of the vaporized sample to the reaction gas supply path
In scan outlet vicinity and thereby arranged in the vicinity of the laser focusing unit, the direction facing the gas outlet in the laser beam irradiated portion of the evaporating sample, and evaporated particles fly toward the sample substrate And an anode is provided on the vacuum chamber side of the gas blowing port. (2) The laser according to the above (1), further comprising a magnetic field generator on the vacuum chamber side of the outlet to generate a magnetic field in a direction in which the evaporated particles of the evaporation sample fly toward the sample substrate. Ion plating equipment.

[0008]

In the present invention, when a reactant gas is introduced into the reactant gas supply passage, the pressure in the reactant gas supply passage becomes higher than the pressure in the vacuum chamber due to the flow path resistance of the gas outlet. For this reason, the increase in pressure near the sample for evaporation increases the plasma density of the discharge, activates the evaporating particles and the reaction gas, and promotes the compounding reaction between the two. Can be prevented from lowering the adhesion to the sample substrate.

Further, by generating a magnetic field along the gas flow in the gas blowing hole, electrons generated together with the evaporating particles due to the discharge are caused to perform cyclotron motion, thereby increasing the collision frequency between the electrons, the evaporating particles and the reaction gas. The activation of the vaporized particles and the reaction gas is further promoted, and the compounding reaction of the two is promoted.

[0010]

FIG. 1 shows an embodiment of the present invention. A reaction gas supply path 2 is installed in a vacuum chamber 1, and an evaporating material 4 made of, for example, a ring-shaped conductive material which is connected to a cathode power supply 3 is installed therein. The reaction gas supply path 2 is vacuum-sealed by a laser introduction window 5. A reaction gas introduction port 6 is provided in the vicinity of the laser introduction window 5, and evaporating particles facing the laser beam irradiated portion of the evaporation sample 4 are removed. It has a gas outlet 7 at the position where it flies. The sample substrate 17 is provided in the traveling direction of the evaporating particles and the reaction gas, and a heater 15 for heating the sample substrate and a bias circuit 16 for applying a negative voltage to the sample substrate are connected.

A small amount of reaction gas is introduced from the reaction gas inlet 6. Laser light 11 oscillated from laser oscillator 10
Is bent in a horizontal direction by a plane mirror 12, condensed by a condenser lens 13, passed through a laser introduction window 5, introduced into a reaction gas supply path 2, and rotated around an axis of a ring-shaped evaporation sample 4. Irradiate the surface tangentially.

In this state, a small current of several tens mA flows due to thermionic emission from the laser irradiation part of the evaporation sample 4. From this state, for example, when the irradiation laser power density is increased to a certain threshold value, the emission of electrons from the laser-irradiated portion rapidly increases, a vacuum arc discharge starts, the arc column 14 is formed, and the amount of evaporated particles rapidly increases. Then, the cathode power supply 3
To adjust the discharge current and the supply amount of the reaction gas. Evaporated particles and reaction gas ionized by the discharge are:
It is heated in advance by the heater 15 and jumps out in the direction of the sample substrate 17 to which a negative bias potential is applied by the bias power supply 16, deposits on the sample substrate, and forms a thin film of a compound composed of evaporating particles and a reaction gas component. . A movable shutter 18 is provided in front of the sample substrate 17 to prevent impurities adhering to the surface of the evaporation sample 4 from being deposited on the sample substrate 17 at the start of evaporation, and to reduce the formation time of the compound thin film. Adjust it arbitrarily. Further, a magnetic field generator 19 is installed near the gas outlet 7 shown in FIG. 2 to generate a magnetic field parallel to the direction in which the evaporated particles fly, thereby increasing the ionization efficiency of the evaporated particles and the reaction gas.

The above is the configuration and operation of the laser ion plating apparatus according to one embodiment of the present invention. Next, as a specific example of the above embodiment, an example of forming a TiN thin film will be described.

As the sample substrate 17, SUS304 alloy, M
o, etc., as an evaporation sample 4, an outer diameter of 30 mm and an inner diameter of
A 0 mm industrial pure Ti ring was used. Also, the sample substrate 1
7, a negative voltage of -200 V was applied by a bias power supply 16 and heated to 150 ° C. by a heater 15. After evacuating the vacuum chamber 1 to a pressure of 3 × 10 ⁻⁴ Pa or less, 20 SCCM of nitrogen was introduced as a reaction gas. At this time, the pressure in the chamber was 4 × 10 ⁻³ Pa, and the pressure in the reaction gas supply passage was about 0.4 Pa. A Q-switched YAG laser beam having a pulse width of 220 ns, a frequency of 1 kHz and a peak power of 130 KW is applied to the outer peripheral surface of the evaporation sample 4 while rotating the ring-shaped evaporation sample 4 to which the cathode power supply 3 is connected at a rotation speed of about 10 rpm. 11 was irradiated with the focus shifted from the tangential direction. Thereafter, the arc discharge was started by adjusting the focal position, the discharge current was adjusted to 0.5 A, and the discharge was continued. Thereafter, the shutter 18 was opened to form a film for 5 minutes.

In this experimental example, 3 μm thick TiN was formed on a SUS304 sample substrate. This film showed a high value of microvickers hardness of Hv2600 and a film adhesion to a substrate of 40 N at a critical load Lc measured by a scratch test.
Also, a TiN film could be formed under the condition that the laser power was 800 W using a CO ₂ laser as the laser beam 11. In this case, the evaporating sample 4 water-cooled the inner surface of the Ti ring to prevent melting and deformation of the Ti ring. In this method, contamination of the laser light introduction window due to the flying of the evaporated particles was not observed, and adhesion to the vacuum chamber was small.

[0016]

According to the apparatus of the present invention, the vaporized particles and the reaction gas are sufficiently combined with each other as compared with the conventional apparatus, and a compound thin film having excellent adhesion to the sample substrate can be formed. In addition, by evaporating the evaporating particles and the reacting gas blowing direction of the gas introduction holes in the gas introduction path to prevent the evaporating particles from diverging due to the gas flow, the evaporating particles can be efficiently attached to the sample substrate. The flow of the reactant gas in the supply path can prevent evaporated particles from flying to the laser introduction window and prevent contamination, thereby enabling stable operation.

[Brief description of the drawings]

FIG. 1 is a schematic view of a laser ion plating apparatus showing one embodiment of the present invention.

FIG. 2 is a diagram of a laser ion plating apparatus provided with a magnetic generator for generating a magnetic field in the vicinity of a reaction gas outlet of FIG.

FIG. 3 is a diagram of a conventional vapor deposition apparatus using vacuum arc discharge.

FIG. 4 shows a diagram of a conventional laser vapor deposition apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum chamber 2 Reaction gas supply path 3 Cathode power supply 4 Evaporation sample 5 Laser introduction window 6 Reaction gas introduction port 7 Gas outlet 8 Anode 10 Laser oscillator 11 Laser light 12 Planar mirror 13 Condenser lens 14 Arc column 15 Heater 16 Bias power supply 17 sample substrate 18 movable shutter 19 magnetic field generator 20 concave mirror

────────────────────────────────────────────────── ─── Continuation of the front page Examiner Yasushi Yamada (56) References JP-A-4-246167 (JP, A) JP-A-2-310363 (JP, A) JP-A-3-104862 (JP, A) Kaihei 3-39464 (JP, A) JP53-18185 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) C23C 14/00-14/58

Claims (2)

(57) [Claims] 1. A laser beam is condensed and irradiated on an evaporation sample to which a negative voltage is applied while introducing a reaction gas into a vacuum chamber, and the laser beam is arranged to face the evaporation sample and a negative bias voltage is applied. In a laser ion plating apparatus for forming a compound thin film comprising a sample material for evaporation and a reaction gas material on a sample substrate, a reaction gas supply path is provided in the vacuum chamber, and the sample for evaporation is supplied to the reaction gas supply path. gas outlet near the inner and together arranged in the vicinity of the laser focusing unit, facing the gas outlet in the laser beam irradiated portion of the evaporating sample, and evaporated particles toward said sample substrate flying A laser ion plating apparatus, wherein the anode is provided on the vacuum chamber side of the gas blowing port. 2. An evaporation test is provided on the vacuum chamber side of the outlet.
2. The laser ion plating apparatus according to claim 1, further comprising a magnetic field generator for generating a magnetic field corresponding to a direction in which the evaporated particles of the material fly toward the sample substrate .