KR20000006648A - Arc/Plasma deposition chamber operable in a wide range of working pressure - Google Patents

Abstract

PURPOSE: An arc/plasma deposition apparatus is provided to solve the problems of limited working pressure, destruction of target protector, and limitation of the size of object. CONSTITUTION: The arc/plasma deposition apparatus comprises a negative pole part(1) including an insulator member positioned at the top of the apparatus, a cathode member positioned below the insulator member and having a magnetron, a cooling line for supplying cooling water to the cathode member, a power line for supplying electric power to the magnetron, the cooling and power lines piercing the insulator part, a target hold for holding a target, and a target protector; a ring-shaped positive pole part(2) positioned below the negative pole part, able to adjust a distance from the target and having a large centric hole and multiple screw holes placed around the centric hole; and a deposition chamber(3) including a wafer support for supporting a wafer and a support height adjustor for adjusting the height of the wafer support, the support height adjustor installing on the bottom of the chamber.

Description

Arc / Plasma deposition chamber operable in a wide range of working pressure}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high performance all-optical arc / electrolyte deposition tank for wideband process partial pressure, and more particularly, to a device for depositing using all-optical arc / electrolyte discharge at a wideband working gas process partial pressure.

Problems of the existing ionizer deposition equipment are as follows.

1) Conventionally, the vacuum deposition process can be deposited only in the range of 3 millitorr (mTorr) to 20 millitorr, and the deposition rate is slow.

2) The target protector is charged with a negative electrode and is made of non-conductive ceramic material (e.g. quartz), so that the surface of the target protector is easily damaged by collision with the ionizer of the working gas (e.g. argon) or thermal stress. have.

3) The short distance between the target surface and the substrate support is less than 5 cm, there is a disadvantage that there is a limit in the size of the object to be deposited.

An object of the present invention for solving the above problems is that problems exist with conventional ionizing deposition equipment, that is, problems that can be deposited only at low working pressure, low deposition rate, limited distance between the target and the substrate, and three-dimensional objects The present invention provides a high performance all-optical / electrode deposition tank for broadband process partial pressure that solves the problem of uniform applicability, extends the process partial pressure to broadband, and solves the easily broken target protection, thereby prolonging the life of the target protective part.

The object of the present invention as described above

1) By applying the all-optical arc method, even if the process partial pressure of the working gas in the vacuum chamber is extended to a wide range of 200 millitorr, it generates and maintains a stable working gas ionizer, improves the deposition rate,

2) The material of the target protector is made of metal (for example, stainless steel) and electrically isolated to prolong the life by preventing collision of the working gas positive electrode formed in the target protector.

3) It is achieved by providing a high performance all-optical / electrolyte deposition tank that makes the distance between the depositable target surface and the substrate holder even greater by about 12 cm.

1 is a cross-sectional view of the upper cathode portion of the deposition tank,

2 is a plan view of the annular anode of the upper cathode portion of the deposition tank,

3 is a schematic diagram illustrating the front assembly of a vapor deposition tank;

Figure 4 is a table measuring the deposition rate according to the diameter of the hole in the annular anode,

5 is a table measuring the deposition rate according to the distance between the target and the annular anode,

6 is a table measuring the deposition rate according to the distance between the target and the substrate,

7 is a table measuring the deposition rate according to the process partial pressure.

<Description of the symbols for the main parts of the drawings>

(1): cathode portion (2): annular anode

(3): evaporation tank (11): cooling water inlet

(12): power supply wire (13): insulator

14: magnet body 15: cathode body

(16): target 17: target hanging

(18): target protector (21): cone-shaped hole

(22): screw hole (31): working gas inlet

(32): double wall (33): starter driving device

(34): ionizer starter 35: screen

(37): handle for driving shade (36): shade shade

(38): substrate support (39): adjusting device

40: cathode portion for substrate load (bias)

As an embodiment of the present invention to achieve the object as described above and to achieve the task for eliminating the conventional drawbacks will be described in detail with reference to the configuration and correlation to the accompanying drawings.

FIG. 1 is a cathode part 1 configured to ionize a working gas with a positive ionizer to cause an all-optical discharge and to ionize particles separated from a target surface, and the upper part of the all-optical / electrolyte deposition tank 3 of FIG. 3 is shown in detail. It is a cross section.

The negative electrode unit 1 has a power supply wire 12 installed in the cathode cooling water inlet 11 and the cathode body through the insulator 13 and connected to the power supply wire 12. The target 16 is fixed to the lower part of the cathode body 15 including the magnet body 14 to be fixed by the target holder 17, and the target shield 18 made of metal material, which is electrically isolated from the outside, is wrapped. It consists of.

In the lower part of the cathode part 1, a ring type anode body 2 having a conical hole in the center is provided at regular intervals from the surface of the evaporation target 16.

The magnet body 14 has an arctic magnet in the center portion, and is surrounded by an antarctic annular magnet around the north pole magnet to maintain the electrons staying on the surface of the target 16 for a long time, and the evaporation rate of the target surface. (sputter yield) can be improved.

Since cooling water is also distributed between the north pole magnet and the south pole magnet of the magnet body 14, heat generated in the target 16 during the deposition process can be efficiently cooled.

The target protector 18 is made of stainless steel, which is resistant to thermal stress, and works from the lower end of the insulator 13 between the cathode body 15 including the magnet body and the lid of the vacuum chamber to the bottom of the target hanger 17. It can be effectively blocked from the positive ionizers of the gas, and the hole facing the target 16 has a diameter of 95 mm which is about 6 mm smaller than the target 16 diameter, so that the ionizer can only occur on the target surface. Consists of.

Since the target protector 18 itself is also electrically isolated to prevent direct collision with positive ionizers of the working gas, the target protector 18 can be used for a longer time than the target protector made of ceramic material, which is generally used for deposition equipment. The dual effect of cost reduction can be obtained.

FIG. 2 is a plan view of the annular anode body 2 detachable to the cathode portion 1, and is composed of a truncated cone-shaped hole 21 and a screw hole 22 used for bonding to the cathode portion 1.

The annular anode body 2 is made of stainless steel, has a thickness of about 1 cm, and is fitted with three supports fixed to the grounding of the lid of the vacuum chamber to the screw hole 22, and then annular. The upper and lower surfaces of the positive electrode 2 are fixed to the negative electrode part 1 by tightening with a female screw having the same size, and are configured to allow distance adjustment from 11 mm to 19 mm from the target surface. A portion of the sieve 2 was cut to prevent contact with the starter inside the vacuum chamber.

The annular anode 2 was used having a cone-shaped hole 21 having a top diameter of 10 cm at the center. The reason for this is that the highest deposition rate was achieved when the annular anodes 2 having a cone diameter of 10 cm were used among the four annular cathodes 2 having a top diameter of 6 cm, 8 cm, 9 cm, and 10 cm. (See FIG. 4).

Referring to FIG. 4 to which the deposition rate is measured by varying the upper diameter of the cone-shaped hole 21 in the annular cathode body 2, it will be described in detail as follows.

Example 1

An annular positive electrode 2 having a top diameter of 6 cm in a cone-shaped hole 21 is coupled to the negative electrode portion 1. The distance between the target surface and the substrate is about 12 cm.

The material of the target 16 uses copper having a diameter of 101.6 mm and a height of 15 mm, a substrate using a microscope insert glass, and a working gas using argon which is relatively inexpensive and has a high evaporation efficiency.

On the substrate, a line is formed in the longitudinal direction and the transverse direction of the substrate using a planetary tool so that the deposition rate of the deposited film can be measured, and the air is removed after the substrate is covered with the shade 35.

When the vacuum in the vacuum chamber reaches 9 × 10 ^-6 Torr, the working gas is introduced into about 10 sccm (standard cubic centimeter per min.) To adjust the process partial pressure in the vacuum chamber to 7 × 10 ^-2 Torr.

Applying a DC voltage to the cathode part 1 generates an ionizer, and after allowing a period of about 5 seconds until the formed ionizer is stabilized, drives the screen 35 so that deposition is performed on the substrate. Afterwards, the substrate is covered again with a shade 35 to prevent further deposition by the remaining ionizer while removing the applied direct voltage.

By moving the shade 35, the time difference between the time when deposition is started on the substrate and the time when the deposition is completed by covering the substrate is set as the deposition time, the time is usually 3 minutes for the thin film is sufficient.

After the deposition is completed, a cooling time of about 5 minutes is allowed to prevent the formation of an oxide layer by reacting the regenerated target surface with the oxygen in the air introduced to break the vacuum before removing the substrate on which the copper deposition is performed. Remove the substrate from the vacuum chamber.

Using a solvent that can dissolve fats and oils (e.g. acetone or alcohol) erases the pre-painted oil paint line on the substrate, and the copper particles deposited on the oil paint line are removed from the A step is formed to fall off, and the step thickness is measured using an alpha step.

As a result of calculating the deposition rate by dividing the measured thickness by the deposition time, a value of 215 nm / min was shown as shown in FIG. 4.

Example 2

Example 2 is the same as Example 1 except that the upper diameter of the cone-shaped hole 21 in the center of the annular anode 2 is 8 cm.

The results of the deposition rate showed a value of about 303 nm / min as shown in FIG. 4.

Example 3

Example 3 is the same as Example 1 except that the upper diameter of the cone-shaped hole 21 in the center of the annular anode body 2 is 9 cm.

The results of the deposition rate showed a value of about 306 nm / min as shown in FIG. 4.

Example 4

Example 4 is the same as Example 1 except that the upper diameter of the cone-shaped hole 21 in the center of the annular cathode body 2 is 10 cm.

The results of the deposition rate showed a value of about 338 nm / min as shown in FIG. 4.

The 10 cm diameter of the cone-shaped hole 21 at the center of the annular anode body 2 exhibiting the highest deposition rate is almost the same as that of the target 16 (about 10.1 cm). The deposition rate was fastest when the distance between the annular anode body 2 having the upper diameter of 21) and the target surface was 11 mm (see FIG. 5).

In the case where the distance between the target surface and the upper surface of the annular anode body is 11 mm and 19 mm using the upper diameter of the cone-shaped hole 21 in the center of the annular anode body 2 is 10 cm Examples of measuring the deposition rate are as follows.

Example 5

The upper diameter of the cone-shaped hole 21 in the center of the annular anode body 2 is fixed to the support with a fastening screw. At this time, the distance between the target surface and the upper surface of the annular anode (2) is 11 mm.

Preparation of the substrate, deposition process, and obtaining the deposition rate after deposition are the same as in Example 1, where the deposition rate is shown in Figure 5 with a value of about 337 nm / min.

Example 6

Example 6 is the same as Example 5 except that the distance between the target surface and the upper surface of the annular anode 2 is 19 mm.

The deposition rate showed a value of about 281 nm / min and is shown in FIG. 5.

The distance between the target surface and the upper part of the annular anode body (2) can be adjusted in 1 mm increments from 11 mm to 19 mm, but measurements were made only at two points, the nearest distance and the farthest distance to see the overall trend.

Of course, it is also possible to adjust the deposition rate by adjusting the distance between the target surface and the top of the annular anode (2) according to the purpose of deposition.

The cone-shaped hole 21 in the center of the annular anode 2 gradually decreases the upper diameter of the surface facing the target surface rather than the lower diameter of the surface facing the inside of the vacuum chamber, as shown in the cross-sectional view of the annular anode 2 of FIG. In order to improve the electron collection during the deposition process, the target evaporation rate of the target surface was improved.

FIG. 3 is a cathode assembly 1 corresponding to FIG. 1 at an upper end of the front assembly diagram of the all-optical arc / electrolyte deposition tank 3.

The working gas inlet 31 is located at one side of the upper wall of the vacuum chamber, and the wall forming the appearance of the deposition tank is composed of a double wall 32 for cooling water distribution for cooling the vacuum chamber.

In the vacuum chamber, a starter driving device 33 is mounted on one side of the upper wall to drive the ionizer starter 34 extending to the wall of the central part of the vacuum chamber.

In conjunction with the shade driving knob 37 mounted outside the bottom wall of the evaporation tank, adjustment is possible, and the support shade 35 moving at the same time is installed at a predetermined distance from the upper part of the substrate support of the vacuum chamber. ,

At the lower end of the shade, a substrate support 38 for supporting the substrate is fixedly supported by the substrate height adjusting device 39 on the bottom wall of the vacuum chamber, and the adjusting device 39 is placed on the upper portion of the cathode portion 40 for loading the substrate. It is provided, the role of the cathode portion 40 is to increase the adhesion between the deposition particles and the substrate separated from the target 16 by the substrate negative voltage applied to the substrate.

In the above, the vacuum chamber of the vapor deposition tank of the present invention was made of stainless steel, and in order to cool the vacuum chamber wall, a double wall 32 was formed to distribute cooling water.

The double wall 32 was welded by connecting the stainless steel bent in a "c" shape in a bracket shape.

If the ion formation is difficult, the starter drive device 33 may be operated to rotate the tip of the starter 34 in the vacuum chamber by about 90 ° to the target surface, causing sparks to forcibly expand the area of the ionizer. In order to adjust the distance between the target surface and the substrate support 38 from 4.5 cm to 11.9 cm, an adjustment device 39 was installed to increase the efficiency of the process conditions for obtaining a fast deposition rate and a stable deposition film. In order to increase the adhesion between the ionizer particles falling off the target surface and the substrate, a negative electrode portion 40 for loading a substrate was installed.

According to the present invention configured as described above, in order to catch the initial vacuum prior to the deposition process, the pressure in the vacuum chamber is first lowered to 3 millitorr by using a rotary vacuum machine (not shown), and then, the coarse copper (adjustment) of the connection between the vacuum tank and the rotary vacuum machine ( roughing) After closing the control valve (not shown) and opening the frontline control valve (not shown), which is a connection between the rotary vacuum machine and the diffusion vacuum machine (not shown), the vacuum in the front face is maintained at about 3 millitorr, and then the vacuum Open the main control valve (not shown), which is the connection control valve of the tank vent and diffusion vacuum, to lower the initial vacuum to 9 x 10 ^-6 Torr.

Thereafter, the main control valve is locked and the working gas is introduced into the vacuum chamber through the working gas inlet 31 connected to the deposition tank to adjust the process pressure for the deposition process to the degree of opening of the gas flow meter (not shown) and the main control valve.

When the process partial pressure inside the vacuum chamber is maintained at 200 millitorr or less, and a DC voltage is applied to the degree of ionizing the working gas between the target 16 of the cathode section 1 and the annular anode body 2, the cathode section Electron particles are emitted from the surface of the target 16 in close contact with (1) to excite the working gas after colliding with the working gas particles, thereby generating a glow discharge while generating positive ionizers of the working gas.

As the DC voltage increases, the current increases, and when it is greater than the threshold current (about 0.1 amp), positively charged working gas ionizers accelerate to the surface of the target 16 in close contact with the cathode, and when the surface strikes, The kinetic energy possessed by the gas ionizers is transferred to the atoms on the surface of the target 16.

At this time, if the kinetic energy is greater than the atomic coupling force and the electron work function (target function) of the target 16, the metal atoms are separated from the target surface.

As the dc voltage continues to increase, the current increases along with the increasing voltage, but the voltage saturates at a certain value and then decreases.

When the voltage saturates and stays at a constant value, the current also stays at a constant value, at which time the discharge proceeds to all-optical arc discharge.

As described above, a direct current voltage is applied between the cathode and the anode to stably maintain the ionizer by gas discharge.

For the positive electrode, an annular positive electrode 2 was used and grounded to the deposition tank.

The ionizing body remains stable even if the process partial pressure of the working gas is changed from 3 to 200 millitorr, and the DC voltage is changed from about 240 volts to about 360 volts according to the target evaporation rate of the target material, and the current is about 6 Change from amperes (A) to 8 amps.

This condition is characterized by much lower voltages and higher currents than in normal blow-off processes.

The voltage and current here are compared with the voltage-current characteristics of the gas discharge, and the discharge has both the characteristics of the light discharge and the characteristics of all-optical discharge.

Fluorescent discharges are townsends in which electrons are formed by any external influence (e.g., when electrons are provided or when external excitation occurs), even at low currents of 10 ^-5 amps or less between the cathode and anode. Townsend) After discharge, it enters the area of normal light discharge up to about 0.1 amp and abnormal light discharge up to 1 amp.

All-optical discharge forms a cathode point where electron emission is concentrated on a target surface when a current of 1 amp or more flows between a cathode and an anode, and a discharge is formed by the electrons emitted from the current, without supply of any working gas. Discharge is maintained in the region.

In this all-optical band, the deposition rate is fast and efficient, and productivity can be increased, and thus, there is a relatively low working cost.

In the deposition tank of the present invention, the ionizer by the light discharge and the ionizer by the photoelectric discharge are mixed so that the generated ionizer is stable, and the deposition rate and efficiency are good.

By utilizing the properties of the ionizer, the deposition rate is high (e.g., 2000 nm / min for copper, see FIG. 6), it is possible to deposit at a broadband process partial pressure (see FIG. 7), and the uniformity of the deposited film can be improved. Jeon Gwang Ho / Ion deposition tank was prepared.

Table 1 below is a table comparing the deposition structure, the deposition conditions and the deposition rate of each embodiment.

TABLE 1

Example Deposition Structure Upper diameter of the conical hole (unit: cm) Deposition Conditions Deposition Rate (nm / min) One Copper / Slide Glass 6 Initial vacuum: 9 × 10 ^-6 Torr Process partial pressure: 7 × 10 ^-2 Torr Working gas flow rate: 10 sccm DC Power: 360-420 V4-7 A Deposition time: 3 minutes 215 2 Copper / Slide Glass 8 303 3 Copper / Slide Glass 9 306 4 Copper / Slide Glass 10 338 5 Copper / Slide Glass 10 (distance between target surface and upper surface of annular anode: 11 mm) 337 6 Copper / Slide Glass 10 (distance between target surface and upper surface of annular anode: 19 mm) 281

The present invention configured as described above

1) It is possible to produce various products requiring different production process conditions with one equipment without additional equipment modification in small quantity production process.

2) It is possible to deposit process pressure up to 200 millitorr,

3) The higher the substrate height, the higher the deposition rate,

4) The damage of the target protective equipment is prevented, and the cathode part except the surface of the target is effectively shielded from the ionizing body by the working gas.

Claims (7)

In the vapor deposition apparatus used at a broadband process partial pressure, The magnet body 14 connected to the power supply wire 12 is installed in the upper portion of the cathode cooling water inlet 11 for cooling and the power supply wire 12 through the insulator insulator 13. The target 16 is fixed to the lower portion of the included negative electrode 15 by the target hanging hook 17, which is electrically isolated from the outside, and the target protector 18 made of a material resistant to thermal stress is wrapped. The cathode part 1 is equipped, Attached to and detached from the lower end of the cathode, the distance is adjusted to the target 16, the center of the cone-shaped hole 21 is drilled, a plurality of screw holes 22 are formed to combine the annular anode body 2 , The working gas inlet 31 is located on one side of the upper wall of the vacuum chamber, and the wall forming the appearance of the deposition tank is composed of a double wall 32 for cooling water distribution for cooling the vacuum chamber. In the vacuum chamber, a starter driver 33 is installed at one side of the wall to drive the ionizer starter 34 extending to the wall of the center of the vacuum chamber. It is connected to the shade driving knob 37 mounted on the outside of the bottom wall of the deposition tank and adjusted, and the shade shade 36 moving while supporting the shade 35 is installed at a predetermined distance from the upper part of the substrate holder of the vacuum chamber. At the lower end of the shade, a substrate support 38 for supporting the substrate is fixedly supported by the substrate height adjusting device 39 on the bottom wall of the vacuum chamber, and the adjusting device 39 is provided at the upper portion of the cathode portion 40 for the substrate load. The ionizer particles are separated from the surface of the target 16 by the negative voltage of the substrate to accelerate the adhesion between the thin film and the substrate. A high performance all-optical / electrolyte deposition tank for wideband process partial pressure, characterized in that the mixture is configured to deposit at a wideband process partial pressure. The method of claim 1, wherein the target protective device 18 is electrically isolated from the lower end of the insulator (13) between the negative electrode body (15) containing the magnet body and the lid of the vacuum chamber to the bottom of the target hook (17), A high performance electro-optic / electrolyte deposition tank for broadband process partial pressure, characterized in that it effectively protects the cathode portion from the positive electrode of the working gas. The high-performance all-optical / electrode deposition tank for broadband process partial pressure according to claim 1, wherein the target protector (18) made of a material resistant to thermal stress is made of stainless steel. 2. The target protector (18) according to claim 1, wherein the target protector (18) drills a hole having a diameter of 95 mm on the side facing the target (16) about 6 mm smaller than the diameter of the target (16) to direct the ionizer to the target (16) surface only. A high performance all-optical / electrolyte deposition tank for broadband process partial pressure, characterized in that to generate. The method according to claim 1, wherein the distance between the surface of the annular anode body 2 and the target 16 is adjustable at intervals of 1 mm to 11 mm to 19 mm depending on the purpose of deposition. High Performance Jeon Gwang Ho / Ion Deposition Tank. The high-performance all-optical / electrode deposition tank for broadband process partial pressure according to claim 1, wherein the annular anode body (2) cuts a part to prevent contact with a starter inside the vacuum chamber. The cone-shaped hole 21 in the center of the annular anode 2 has a smaller upper diameter of the surface facing the target surface than the lower diameter of the surface facing the inside of the vacuum chamber, so as to facilitate electron collection. A high performance all-optical arc / electrolyte deposition tank for broadband process partial pressure, characterized in that.