JP4109751B2 - Method for filling evaporation raw material in PVD apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of filling evaporation material in a PVD apparatus in which a plasma beam is guided by a magnetic field onto the evaporation material in a vacuum chamber.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a PVD apparatus in which a plasma beam generated by a plasma gun is guided by a magnetic field onto a powdery, granular, or pelletized evaporation raw material housed in a crucible in a vacuum chamber is known. In the vacuum chamber, the evaporation material is evaporated by a plasma beam, and a thin film is formed on the lower surface of the substrate located above the evaporation material.
[0003]
Incidentally, in the PVD apparatus, to continue for a long time continuously thin film formation, it is necessary to compensate for the decrease amount of the vaporized raw material contained in a crucible, having a sectional shape narrowed downward, as shown in FIG. 7, for example Supply and filling of the evaporation raw material M from the feeder 51 to the crucible 52 is performed.
In addition, as shown in FIGS. 8 and 9 , the blade 54 is arranged in parallel in the vicinity of the feeder 53 having the same shape as described above, and the evaporation raw material M is transferred from the feeder 53 to the crucible 55 while reciprocating the crucible 55 horizontally. A method is also employed in which the upper surface of the evaporation material M is scraped off by the blade 54 to prevent excessive supply of the evaporation material M, and the evaporation material M is filled while the upper surface of the evaporation material M is smoothed.
[0004]
[Problems to be solved by the invention]
In the case of the method shown in FIG. 7 among the above-described methods for filling the evaporation raw material M, the evaporation raw material M is simply dropped from the feeder 51 and supplied to the crucible 52. Therefore, the evaporation raw material M in the crucible 52 is supplied. The packing density is not uniform. Moreover, in this method, the upper surface of the evaporation raw material M supplied to the crucible 52 is not smooth. For this reason, the deposition rate during film formation in the PVD apparatus becomes unstable, and the film thickness distribution in the direction of movement of the thin film to the substrate and in the direction perpendicular thereto is not uniform, but also the substrate and the thin film. As a result, there arises a problem that the entire thickness including the material also varies between products.
[0005]
Further, in the case of the method shown in FIGS. 8 and 9 , the upper surface of the evaporation raw material M in the crucible 52 is smoothed more than the method described above, but the smoothness is not always sufficient. Further, the filling density of the evaporation raw material M is still non-uniform. For this reason, although there is a slight difference, the same problem as described above occurs.
The present invention has been made with the object of eliminating such conventional problems, and is a method for filling an evaporation material in a PVD apparatus capable of uniforming the thickness of the formed thin film and improving variation among products. Is to provide.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides a plasma beam generated by a plasma gun, rotating the two concentric circles powdery or granular accommodated in a crucible having a ring-shaped groove the edge of the vacuum chamber Alternatively, in the method of filling the evaporation material in the PVD apparatus in which a thin film is formed on the lower surface of the substrate positioned above the evaporation material by a magnetic field on the pellet-shaped evaporation material, the evaporation not irradiated with the plasma beam in the crucible The evaporating raw material is supplied to the weight reducing part of the raw material by a feeder during thin film formation, and then the upper surface of the new evaporating raw material supply part is smoothed to a certain thickness, and the filling density of the newly supplied evaporating raw material is reduced. It was made to keep constant by rotation of the roll press-contacted on the said edge part .
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows an evaporating raw material filling portion of a PVD apparatus to which the filling method according to the present invention is applied. A crucible 1 is a ring shape in which two concentric circles form an edge portion 2 of an evaporating raw material M in powder form, granular form or pellet form. And can be rotated in the direction of the arrow by a driving device at the bottom of a vacuum chamber (not shown) of the PVD apparatus. Reference numeral 4 denotes a sheet-formed plasma beam guided onto the evaporation material M by a magnetic field by a plurality of magnets (not shown) disposed below the crucible 1.
Then, at the position of the crucible 1 facing the plasma beam 4 (the reduced portion of the evaporated raw material M not irradiated with the plasma beam 4), the evaporated raw material supply feeder 5 and the blade 7 are directed outward of the crucible 1. A frustoconical roll 8 having an increasing diameter is provided.
The evaporating material supply feeder 5 is positioned upstream of the crucible 1 in the rotational direction, the roll 8 is positioned downstream, and the blade 7 is positioned intermediate.
[0008]
The roll 8 is supported at both ends by a bearing box 9 so as to be in pressure contact with the annular edge 2 of the crucible 1, and the lower end of the blade 7 is at a height with a gap D ₁ from the upper surface of the crucible 1 , bottom opening of the feeder 5 is further disposed at a height that a gap D _2. (See Figure 5.)
[0009]
Therefore, in the vacuum chamber, the evaporation source M filled in the rotating crucible 1 is evaporated by the plasma beam 4, and the evaporation source M is deposited on the lower surface of the substrate (not shown) moving above the crucible 1 by vapor deposition. Is formed.
[0010]
When the evaporation material M in the crucible 1 is reduced in this way, when the evaporation material M is supplied from the feeder 5, the supplied evaporation material M has a constant thickness via the gap D ₁ at the lower end of the blade 7. And is conveyed toward the roll 8 and the pressing surface is uniformly pressed by the roll 8 at a fixed position, so that the upper surface of the evaporation raw material M is sufficiently smoothed and newly added to the crucible 1. The packing density of the supplied evaporation raw material M is kept constant as a whole.
[0011]
As a result, not only can the thin film formation be continuously continued for a long time, but also the film thickness of the thin film formed on the substrate (not shown) becomes uniform as a whole, resulting in variations among products. Improved.
The optimum amount of the evaporation material M to bring up the roll 8, the evaporation material M is determined according to the weight loss rate and the particle size or pellet size of the evaporation material M, of the D _1, D ₂ accordingly size Is adjusted.
[0012]
In the above description, the roll 8 has a truncated cone shape, but may have a cylindrical shape as shown in FIG.
However, the surface particles of the evaporation material M by the use of rolls 8 formed in a truncated cone shape and the speed of the outer peripheral surface each part of the roll 8 in contact with the upper surface each part of the evaporation material M and which in the same, there is a speed difference It is possible to minimize the occurrence of the problem of unnecessary fine grinding.
[0013]
In addition, a rack is provided on the edge 2 of the crucible 1, while a pinion that meshes with the rack is provided on the roll 8, and the roll 8 is forcibly rotated in conjunction with the rotation of the crucible 1, and the rotation of the roll 8 is unstable. Even in such a case, a constant rotation speed may always be ensured.
[0014]
Further, a tray portion (concave portion) that receives the evaporated raw material M spilled from the crucible 1 may be provided on the entire outer periphery of the side of the crucible 1 so that the evaporated raw material M spilled from the crucible 1 may be recovered.
[0015]
Furthermore, while omitting the blade 7, as shown in FIG. 6, a protruding portion 6 directed toward the roll 8 side may be provided at the lower end portion of the feeder 5 so as to have a function as the blade 7.
[0016]
【The invention's effect】
As is apparent from the above description, according to the present invention, the plasma beam generated by the plasma gun is stored in a crucible having a ring-shaped groove with two rotating concentric circles as edges in the vacuum chamber. Alternatively, in the method of filling the evaporation material in the PVD apparatus in which a thin film is formed on the lower surface of the substrate positioned above the evaporation material by a magnetic field on the granular or pellet evaporation material, the plasma beam in the crucible is irradiated. The evaporation material is supplied to the weight reduction part of the evaporation material during the thin film formation by a feeder , and then the upper surface of the new supply part of the evaporation material is smoothed to a constant thickness and filled with the newly supplied evaporation material. The density is kept constant by the rotation of the roll pressed against the edge .
[0017]
Thus, in the thin film formation by supplying a new evaporation raw material loss of the crucible, as well as smoothing the upper surface of its constant thickness, rotating the packing density of the vaporized raw material this newly supplied in roll because you have to keep constant by the thickness of the thin film that will be formed on the substrate whole becomes uniform, the improvement variations among products, moreover continuously be thin form for a long time, productivity There is an effect that you improve.
[0018]
[Brief description of the drawings]
FIG. 1 is a plan view showing an evaporating material filling unit to which an evaporating material filling method is applied in a PVD apparatus according to the present invention.
FIG. 2 is a diagram showing an outline of a cross section of the evaporation raw material filling portion shown in FIG . 1;
FIG. 3 is a partial perspective view showing an outline of an evaporating raw material filling unit shown in FIG.
FIG. 4 is a plan view showing an outline of another evaporation raw material filling unit to which the filling method according to the present invention is applied.
5 is a diagram showing distances from the feeder, blade, and roll crucible edge in FIG . 1. FIG.
FIG. 6 is a diagram showing a case where a blade is also used as a part of the feeder.
FIG. 7 is a cross-sectional view schematically showing an evaporation raw material filling portion in a PVD apparatus to which a conventional filling method is applied.
FIG. 8 is a cross-sectional view schematically showing an evaporating raw material filling portion in another PVD apparatus to which a conventional filling method is applied.
9 is a cross-sectional view taken along an arrow in FIG.
[Explanation of symbols]
1 crucible, 2 edge, 4 plasma beam,
5-Feeder for evaporating raw material supply, 6-Overhang part, 7-Blade,
8-roll, M-evaporation raw material.

Claims (1)

The plasma beam generated by a plasma gun, guided by the two magnetic field concentric edges become annular and housed in a crucible with a groove powdery or granular or pellet-like evaporation on raw materials which rotates in the vacuum chamber, In the method of filling evaporation material in a PVD apparatus for forming a thin film on the lower surface of the substrate positioned above the evaporation material, the evaporation material is formed during thin film formation in the reduced portion of the evaporation material not irradiated with the plasma beam in the crucible. was supplied by the feeder, then while smoothing the upper surface of the new supply of the evaporation material to a predetermined thickness, constant by rotation of the roll for pressing the packing density of the vaporized raw material newly supplied onto the edge A method for filling an evaporation material in a PVD apparatus, characterized by being maintained at a constant temperature.

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