JPH02309630A - Sputtering device - Google Patents

Abstract

PURPOSE:To reduce power consumption and hence improve preheating efficiency and shorten processing time by disposing a heat reflecting plate over the entire surface of a wafer located at a gap where the wafer and a target are opposed upon the preheating of the wafer, and removing the same upon sputtering. CONSTITUTION:A heat reflecting plate 20 comprises a metal plate (e.g. 3mm thickness) finished in its surface to a mirror surface, which plate is disposed at a position separated 2-3mm from the front surface of a wafer 1, configured in its external surface to the same size as that of the wafer 1. Further, the heat reflecting plate 20 is set such that it can be removed from a gap where the wafer 1 and a target 3 are opposed, by rotation of a moving lever 21. Additionally, the heat reflecting late 20 is disposed at the front of the wafer 1 facing the same upon preheating to prevent heat from being dissipated from the surface of the wafer 1, and the heat reflecting plate 20 is eliminated from the surface of the wafer 1 upon sputtering. Hereby, effective preheating can be achieved together with the reduction of power consumption and the reduction of processing time.

Description

[Detailed Description of the Invention] [Summary] Regarding the improvement of sputtering equipment used for film formation, the purpose of this invention is to efficiently heat a film-forming substrate and raise the temperature to a predetermined temperature in a short time. A heat reflecting plate is arranged in front of the film-forming substrate in a gap facing the target, and the heat-reflecting plate is arranged in front of the film-forming substrate during preheating of the film-forming substrate, and the sputtering process is performed. It is characterized in that it is sometimes removed from the front surface of the film-forming substrate.

[Industrial application field]

The present invention relates to improvements in sputtering equipment used to form coatings when manufacturing electronic components such as semiconductor devices.

[Conventional technology]

For example, in the manufacturing method of semiconductor devices such as ICs and LSIs, aluminum, its alloys, or high melting point materials such as molybdenum and tungsten are used as wiring materials, and sputtering is used to form such films. ) equipment is used.

In order to adapt to the automation of wafer processes, such sputtering equipment performs continuous single-wafer processing, and Figure 2 shows a cross-section of the main parts of the conventional single-wafer sputtering equipment. There is. In the figure, symbol 1 is a wafer (film formation substrate), 2 is a heating stage, 3 is a target, 4 is a backing plate, 5 is a power source, and 6 is a side wall of the processing chamber.

11 is an Ar (argon) gas inlet port 1.12 is a total gas inlet port (2).

To explain the operation outline, several hundred volts of direct current or alternating current (frequency 13.56?1H2) electricity a5 is applied between the wafer l held on the heating stage 2 and the target 3 held on the backing plate 4. Then, Ar gas was introduced into the processing chamber from the Ar gas inlet I to reduce the pressure to several mTorr, and the inflowing Ar gas was ionized.
The gas ions are made to collide with the target 3, and the coating atoms are ejected and deposited on the wafer 1. At that time, the wafer 1 is placed on the heating stage 2, for example with a presser spring 2S.
In addition, several quadrilateral heaters 2H are embedded in the heating stage 2 so that the wafer can be heated. However, the pressure inside the processing chamber is reduced to several m Torr, and heat is transferred through the gap between the heating stage 2 and the wafer 1 only by radiant heat, resulting in poor thermal efficiency. To do this, a gauge gas is introduced between the back surface of the wafer and the heating stage 2 through the gauge gas inlet 2, the pressure in the gap is increased to several Torr, and the wafer 1 is heated using heat conduction by the gas. There is. That is, the same gas as the sputtering gas is used to prevent gas leakage from the gap from affecting the heat conduction using Ar gas.

On the other hand, the backing plate 4 that holds the target 3 is made of a copper plate that circulates cooling water inside to cool down the heat generated by the target 3 due to the collision of the ion gas. The backing plate 4 has an O-ring 4P interposed between it and the processing chamber side wall 6 so that it can be attached and detached.

In addition, the entire processing chamber is equipped with a powerful exhaust system (
Both are not shown; located on the left side of the figure) for suction and exhaust, and the wafer 1 is fed in and out from a load rotor chamber arranged perpendicular to the plane of the paper. and the wafer 1 is placed on the heating stage 2.
It is also provided with a mechanical part (not shown) that tilts in the horizontal direction and allows attachment and detachment of wafers.

[Problems to be Solved by the Invention] However, when performing sputtering using the sputtering apparatus configured as described above, the temperature of the wafer must be increased to 400 to 600℃.
For example, when raising the temperature to 00°C, according to the current equipment, it takes 60 to 90°C to raise the temperature to that temperature.
However, the heating efficiency is such that the temperature only rises to about 100 to 150°C lower than the set temperature of the heater built into heating stage 2, and equilibrium is maintained at that low temperature. There is badness.

Figure 3 is a diagram showing the relationship between heating temperature and time, and the heating curve by a conventional sputtering device is shown in curve ■, and the data is an example when the set temperature of the heater is 500°C. However, as shown in the figure, the equilibrium temperature is reached within 60 to 90 seconds, and the equilibrium temperature is approximately 360 to 380°C.

Then, since the processing efficiency of sputtering equipment as part of an automated system is low, the present invention proposes a sputtering equipment whose purpose is to efficiently heat a wafer and raise the temperature to a predetermined temperature in a short time. be.

[Means to solve the problem]

As shown in FIG. 1, the problem is that a heat reflecting plate 20 is disposed in front of the wafer in a gap where a wafer (film-forming substrate) 1 and a target 3 face each other. This is solved by a sputtering device which is placed on the front side of the wafer during preheating of the wafer and removed from the front side of the wafer during sputtering.

[Function] That is, the present invention aims to improve heating efficiency by arranging a heat reflecting plate on the front surface of the wafer to prevent heat from dissipating from the wafer surface during preheating. and its movable parts.

〔Example〕

Examples will be described in detail below with reference to the drawings.

FIG. 1 shows a cross-sectional view of the main parts of a single-wafer type sputtering apparatus according to the present invention, and the symbols in the figure are the same as in FIG.
1 is the wafer, 2 is the heating stage.

3 is the target, 4 is the backing plate, 5 is the power supply,
6 is a processing chamber side wall, 11 is an Ar gas inlet I, and 12 is an Ar
In the gas inlet (2), 20 is a heat reflecting plate, and 21 is a movable rod for the heat reflecting plate.

The heat reflecting plate 20 is a metal plate (W-SA3) with a mirror-finished surface.
mm), and is arranged at a position 2 to 3 mm from the front surface of the wafer 1, and has the same external size as the wafer, for example, a diameter of 150 mmφ. Such a heat reflecting plate 20
By rotating the moving rod 21, the wafer l and target 3 are
The structure is such that it can be removed from the gap facing the Note that the movement of the heat reflecting plate 20 is not by rotation as in this embodiment, but other methods may also be considered.

Thus, preheating can be performed efficiently by placing the heat reflecting plate 20 facing the front surface of the wafer during preheating and removing it from the front surface of the wafer during sputtering. The heating curve by the sputtering device is shown in curve ⋯ in the relationship between heating temperature and time in Figure 3, and the set temperature of the heater is 500'.
C, the equilibrium temperature is reached in 30 to 60 seconds, which is shorter than the conventional device, and the equilibrium temperature rises to nearly 500°C, which is about 100°C higher than the conventional device. I understand.

To explain the concrete implementation results, in an example in which an Al-1χSt film with a film thickness of 1 μm is deposited on the surface of a silicon substrate with a diameter of 150 mmφ on which a silicon oxide film (film thickness of 3000 μm) is provided,
Introduce metering gas from the Ar gas inlet (■) to maintain the pressure in the gap between the back surface of the wafer and the heating stage 2 at approximately IT.

rr, Ar gas is introduced from the Ar gas inlet I, the pressure inside the processing chamber is adjusted to 3 mTorr, and the heat reflection Fi
, 20, the preheating time is halved compared to the case without the reflector, and the equilibrium temperature reached is reduced by 50~
We were able to raise the temperature by 100°C.

Therefore, the sputtering apparatus according to the present invention can improve preheating efficiency and reduce power consumption, and the operation of the movable rod 21 for inserting and removing the heat reflecting plate 20 can be automatically operated by the sputtering apparatus. If incorporated, it becomes possible to use the sputtering apparatus significantly more efficiently than before.

〔Effect of the invention〕

As is clear from the above description, the sputtering apparatus according to the present invention has the remarkable effect of reducing power consumption, improving preheating efficiency, and shortening processing time, thereby improving the efficiency of automated systems in wafer processes. This will greatly contribute to the

Further, although the above example uses a method of manufacturing a semiconductor device as an example, it is of course applicable to a method of manufacturing other electronic components.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part of a sputtering apparatus according to the present invention, FIG. 2 is a sectional view of a main part of a conventional sputtering apparatus, and FIG. 3 is a diagram showing the relationship between heating temperature and time. In the figure, ■ is a wafer (film formation substrate), 2 is a heating stage, 3 is a target, 4 is a backing plate, 5 is a power source, 6 is a side wall of the processing chamber, and 11 is an Ar gas inlet I. 12 is an Ar gas inlet (2), 20 is a heat reflector, and 21 is a movable rod for the heat reflector.

Claims (1)

[Claims] A heat reflecting plate (20) is arranged in front of the film forming substrate in a gap where the film forming substrate (1) and the target (3) face each other, and the heat reflecting plate is a spare part of the film forming substrate. A sputtering apparatus characterized in that it is arranged in front of a film-forming substrate during heating and is removed from the front surface of the film-forming substrate during sputtering processing.