| 摘要 |
A method and apparatus for fabricating a metamorphic long-wavelength, high-speed photodiode, wherein a buffer layer matching a substrate lattice constant is formed at normal growth temperatures and a thin grading region which grades past the desired lattice constant is configured at a low temperature. A reverse grade back is performed to match a desired lattice constant. Thereafter, a thick layer is formed thereon, based on the desired lattice constant. Annealing can then occur to isolate dislocated material in a grading layer and a reverse grading layer. Thereon a strained layer superlattice substrate is created upon which a high-speed photodiode can be formed. Implant or diffusion layers grown in dopants can be formed based on materials, such as Be, Mg, C, Te, Si, Se, Zn, or others. A metal layer can be formed over a cap above a P+ region situated directly over an N-active region. The active region also includes a p-doped region. The high-speed photodiode can thus be formed utilizing GaAs, or other substrate material, such as germanium and silicon.
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