Crystal substrates and methods of fabricating the same

Abstract

A single crystal substrate and method of fabricating the same are provided. The single crystal substrate includes an insulator having a window exposing a portion of a substrate, a selective epitaxial growth layer formed on the portion of the substrate exposed through the window and a single crystalline layer formed on the insulator and the selective epitaxial growth layer using the selective epitaxial growth layer as an epitaxial seed layer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Example embodiments will become more apparent by describing in detail the attached drawings in which:

FIGS. 1A and 1B are schematic cross-sectional views illustrating crystal silicon substrates having crystal layers crystallized through lateral thermal gradients, according to an example embodiment;

FIGS. 2A and 2B are schematic cross-sectional views illustrating crystal silicon substrates having lateral crystal layers crystallized through seed layers, according to an example embodiment;

FIGS. 3A and 3B are cross-sectional views illustrating crystal germanium substrates having lateral crystal layers crystallized through seed layers, according to an example embodiment;

FIGS. 4A through 4J are cross-sectional views illustrating a method of fabricating a crystal silicon substrate, according to an example embodiment;

FIG. 5A is a scanning electronic microscopy (SEM) image illustrating a sample of a fabricated crystal silicon substrate, according to an example embodiment;

FIG. 5B is an enlarged image of a square portion of the SEM image illustrated in FIG. 5A, according to an example embodiment;

FIG. 6A is an SEM image illustrating a sample of a successfully crystallized crystal silicon substrate, according to an example embodiment; and

FIG. 6B is an enlarged SEM image of the sample illustrated in FIG. 6A, according to an example embodiment.

Claims

1. A crystal substrate comprising: a crystalline substrate;a laterally-crystallized crystalline layer in parallel with the crystalline substrate; anda polishing stopper buried in the laterally crystallized crystalline layer for limiting a polishing depth of the laterally crystallized crystalline layer.

2. The crystal substrate of claim 1, further including an insulator arranged between the crystalline substrate and the laterally crystallized crystalline layer for inducing lateral growth of the laterally crystallized crystalline layer.

3. The crystal substrate of claim 2, wherein a window is formed in the insulator to expose the crystalline substrate.

4. The crystal substrate of claim 2, wherein a seed layer is formed in the window using selective epitaxial growth.

5. The crystal substrate of claim 1, wherein the crystalline substrate is a sapphire substrate, a silicon substrate or a germanium substrate.

6. The crystal substrate of claim 2, wherein the insulator is a silicon oxide (SiO2) insulator.

7. The crystal substrate of claim 2, wherein the insulator has a stack structure.

8. The crystal substrate of claim 7, wherein the insulator further includes, a SiO2 insulator, anda silicon nitride layer stacked on the SiO2 insulator.

9. A method of fabricating a crystal substrate, the method comprising: forming a stopper on a crystalline substrate;forming an amorphous layer burying the stopper on the crystalline substrate;melting and solidifying the amorphous layer to form a crystalline layer crystallized in parallel with the crystalline substrate; andpolishing the crystalline layer to an upper portion of the stopper.

10. The method of claim 9, further including, forming an insulator having a window on the crystalline substrate to expose a surface of the crystalline substrate before forming the stopper.

11. The method of claim 9, further including, forming an epitaxial growth seed layer on a portion of the surface of the crystalline substrate exposed through the window.

12. The method of claim 9, wherein the crystalline substrate is a silicon substrate, a sapphire substrate or a germanium substrate.

13. The method of claim 10, wherein the insulator includes at least one of a SiO2 layer and a SiNx layer.

14. The method of claim 10, wherein the insulator is formed to have a stack structure.

15. The method of claim 14, wherein the stack structure includes a SiO2 layer and a SiNx layer stacked on the SiO2 layer.

16. The method of claim 10, wherein the forming of the insulator further includes, alternately stacking layers of SiO2 and SiNx.

17. The method of claim 9, wherein the amorphous layer is an amorphous silicon layer or an amorphous germanium layer.

18. The method of claim 9, wherein the amorphous layer is a polycrystalline silicon layer or a polycrystalline germanium layer.

19. The method of claim 9, wherein the amorphous layer includes polycrystalline silicon.

20. The method of claim 9, wherein the amorphous layer is melted using excimer laser annealing.

21. The method of claim 9, wherein the insulator is formed using chemical vapor deposition or sputtering.

22. The method of claim 9, further including, annealing a crystallization target material after melting but before solidifying the amorphous layer.