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AssigneeCanon Kabushiki Kaisha
InventorsNoritaka Ukiyo, Tetsuro Saito, Tatsumi Shoji, Makoto Iwakami, Takehito Yoshino, Shoji Nishida, Masaaki Iwane, Masaki Mizutani
Estimating the term…
A method for producing semiconductor thin films in which the semiconductor thin films are allowed to grow on a plurality of substrates by dipping the plurality of substrates into a solution filled in a crucible, the solution containing a semiconductor as a solute, while moving the same in the solution. An angle between a direction of a normal line on a central portion of a growing surface of each substrate and the direction of the movement of the substrates is set to be in 87 degrees or less and the movement of the substrates generates a flow of the solution.
A method for producing semiconductor thin films, which comprises:
A method for producing semiconductor thin films, which comprises:
A method for producing semiconductor thin films, which comprises dipping a plurality of substrates into a solution filled in a crucible, the solution containing a semiconductor as a solute, and growing the semiconductor thin films on the plurality of substrates while moving the plurality of substrates in the solution,
A method for producing semiconductor thin films which comprises:
A method for producing semiconductor thin films which comprises:
A method for producing semiconductor thin films which comprises:
A method for producing semiconductor thin films which comprises:
Dependencies are inferred from the claim text.
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Elements: silicon
Reaction chambers; Boats for supporting the melt; Substrate holders: vertical dipping system
Single-crystal growth
Term ended 28 Sep 2021 (estimated)
1. Field of the Invention
The present invention relates to a liquid phase growth method and a liquid phase growth apparatus, specifically to a liquid phase growth method and a liquid phase growth apparatus for forming substrates which can be used for producing semiconductor devices, in particular, such as solar cells and optical sensors.
2. Related Background Art
FIGS. 1A and 1B are sectional views of a dipping type Si liquid phase growth apparatus of the prior art;
FIG. 2 is a sectional view of the dipping type Si liquid phase growth apparatus of the prior art;
FIG. 3 is a perspective view showing a main part of the apparatus of FIG. 2;
The reasons for the variations in film thickness and quality among the semiconductor thin films growing on respective substrates and for the wide distribution of the thickness and quality in a single substrate surface are that the concentration of the solute (a semiconductor such as silicon) of the solution in the crucible and the temperature of the solution differ from part to part. And, as means for minimzing the above variations and distribution, it is considered that an agitating mechanism is provided within the crucible so as to forcibly circulate the solution; however, this is not preferable because the apparatus becomes intricate and a wider space is required within the crucible. Thus, in the present invention, means for effectively agitating the solution and enhancing the uniformity of the solution is provided without any intricate mechanism.
That is, as shown in FIG. 28, in growing a semiconductor thin film on a predetermined surface (growing surface) of each of the plurality of substrates, which have been dipped into a solution containing a semiconductor which is filled in a crucible, while moving the substrates as an integral unit in the predetermined direction, each substrate is arranged in such a manner that the normal line on the center of the growing surface of each substrate thereof makes a predetermined angle of θ degrees to the direction of the substrate movement. As a result, the solution flows along the surface of each substrate and moves from region A at one side of the substrate line consisting of multiple substrates to region B at the other side of the same substrate line. Since the flow crossing the substrate line from the region A to the region B can generate the circulation of the solution in the crucible, the solute concentration and the temperature become uniform in the solution.
However, if the angle θ is too small, the flow of the solution is blocked by the ends of each substrate and does not cross the substrate line, as shown in FIG. 29, consequently the flow from the region A to the region B cannot be generated. Further, the solution holds up between the substrates and the concentration of the solute is likely to decrease locally at the central portion of each substrate. The angle θ of 5 degrees or less may cause such a situation.