JPH0342034Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to a thin film forming apparatus for depositing metal vapor onto a substrate.

[Conventional technology]

Figure 2 shows a cross section of a conventional thin film forming apparatus. In the figure, 1 is a crucible, 2 is a metal placed in the crucible 1 to be melted, and 3 is a metal placed in the upper part of the crucible 1 to be melted. Hole from which metal 2 spews out, 4
5 is a filament that heats the crucible 1; 6 is an AC power source that causes current to flow through the filament 5 to raise it to a high temperature and emit electrons; 7
is a crucible 1 in which electrons are emitted by an AC power source 6
A first DC power source has a bias voltage that makes the potential of the crucible 1 more positive than the potential of the filament 5 so that the potential of the crucible 1 collides with the filament 5; 8 is an ionizing filament that emits electrons; An accelerating grid; 10 is an AC power source that causes the ionizing filament 8 to generate heat; 11 is a second DC power source that keeps the ionizing filament 8 at a negative potential with respect to the grid 9; 12 is an accelerating electrode that accelerates the ionized metal vapor 4; 13 is a substrate on which a metal thin film is deposited; 14 is a deposited film; 15 is a third DC voltage that gives the acceleration electrode 12 a more negative potential than the grid 9; 16 is a heat shield plate that prevents heat radiation from the crucible 1; 17 is a vacuum chamber.

In FIG. 2, the filament 5 is connected to the AC power source 6.
The heated electrons are emitted, but due to the positive voltage applied to the crucible 1 by the first DC power source 7, the thermoelectrons collide with the crucible 1 and heat the crucible 1. The metal 2 in the crucible 1 evaporates and is ejected from the hole 3 into the vacuum. In the ejected metal vapor 4, electrons ejected from the filament 8 pass through the grid 9 and hit the metal vapor 4, ejecting electrons and becoming positively charged ions. These positive ions are accelerated by the heating electrode 12 and deposited on the substrate 13 to form a deposited film.

[Problem that the invention attempts to solve]

Since the conventional thin film forming apparatus is configured as described above, a part of the vapor that is not ionized in the ejected metal vapor 4 is not subjected to the force of the accelerating electrode 12, so it loses its initial velocity and diffuses as shown by the arrow. It goes around the vicinity of filament 5. These vapors are extracted by electrons flowing out from the filament 5 and become positive ions, and the purpose is to obtain a thin film forming device that can stabilize the AC power source 6 of the filament 5. .

[Means for solving problems]

In the thin film forming apparatus according to this invention, as shown in FIG. 1, the hole side of the crucible is surrounded by a shield to prevent ejected metal vapor from entering the filament side.

[Effect]

The thin film forming apparatus according to this invention not only improves vapor deposition efficiency but also stabilizes the power source of the filament because the metal vapor does not enter the filament side due to the shield.

[Example of idea]

An embodiment of this invention will be described below with reference to the drawings. In FIG. 1, 1 to 17 are the same as those in the conventional embodiment, so their explanations will be omitted.

18 is a deep dish-shaped shield attached to the hole 3 side of the crucible 1. Deep dish-shaped shield 1 above
The metal vapor 4 ejected by the metal vapor 8 is sent to the grid 9 where ionization is performed without going around to the filament 5 side.

[Effect of idea]

As described above, according to this invention, the shield is configured so that metal vapor can be efficiently deposited, and is also provided to prevent metal vapor from getting around the filament, so the power source can be kept stable and high quality can be achieved. This has the effect of producing a thin film.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a thin film forming apparatus according to an embodiment of this invention, and FIG. 2 is a sectional view showing a conventional thin film forming apparatus. In the figure, 1 is a crucible,
3 is a hole, 4 is a metal vapor, 5 is a filament, 17
is a vacuum chamber, and 18 is a shield. In each figure, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Scope of utility model registration request] a vacuum chamber, a filament disposed inside the vacuum chamber, a crucible that is heated by the filament and ejects metal vapor from a hole in the top;
and located between the hole and the filament,
A thin film forming apparatus comprising a shield that prevents metal vapor ejected from the hole from flying near the filament.