Apparatus for making epitaxial film
An apparatus for growing an epitaxial film and transferring it to an assembly substrate is disclosed. The film growth and transfer are made using an epitaxy lateral overgrowth technique. The formed epitaxial film on an assembly substrate can be further processed to form devices such as solar cell, light emitting diode, and other devices and assembled into higher integration of desired applications.
1. An apparatus for forming an epitaxial thin film comprising:
a melt pocket for holding a liquid phase epitaxial material;
a manifold for directing said liquid phase epitaxial material onto an assembly substrate;
first frame portion with a body adapted to hold said assembly substrate, which assembly substrate can include a plurality of openings;
a second base portion adapted to hold a seed substrate in contact with said assembly substrate such that said liquid phase material can be introduced into a template within said assembly substrate and contact a surface of said seed substrate through said plurality of openings;
a temperature controller for controlling melting and cooling of said liquid phase epitaxial material such that an epitaxial layer can be formed as a patterned epitaxial structure within said frame portion above said assembly substrate;
a transfer mechanism that can operate in conjunction with said temperature controller and which is adapted to move said first frame portion and/or said second base portion so as to separate said epitaxial layer and patterned epitaxial structure from said seed substrate;
wherein said epitaxial layer and patterned epitaxial structure can be transferred within said assembly substrate as a distinct layer from said seed substrate.
2. The apparatus of claim 1 wherein said melt pocket and manifold are movable relative to said assembly substrate.
3. The apparatus of claim 1 wherein said epitaxial layer can be formed with graded characteristics including one of a graded composition and/or doping profile.
4. The apparatus of claim 1 wherein said epitaxial layer can be used to form a p-n junction for an integrated circuit device.
5. The apparatus of claim 1 wherein said transfer mechanism uses a physical shearing action.
6. The apparatus of claim 1 wherein said temperature controller can cooperate with a movable assembly to separate said epitaxial layer from said seed substrate using a reheating process.
7. The apparatus of claim 1 wherein said assembly substrate and epitaxial layer can be further processed like a conventional semiconductor wafer in subsequent processing steps to form additional active devices on said assembly substrate and/or said epitaxial layer.
8. The apparatus of claim 1 wherein said seed substrate can be re-used after said epitaxial layer is separated for growing a second epitaxial layer.
9. The apparatus of claim 1 wherein multiple assembly substrates and epitaxial layers can be stacked on top of each other within the apparatus during an epitaxial growth process.
10. The apparatus of claim 1 wherein said second base portion is a recessed cavity within a boat assembly.
11. The apparatus of claim 1 wherein said epitaxial layer can be formed with graded characteristics including one of a graded composition and/or doping profile.
12. The apparatus of claim 1 wherein said epitaxial layer can be used to form a p-n junction for an integrated circuit device.