N-type doping of strained epitaxial germanium films through co-implantation and nanosecond pulsed laser melting

Patent metadata

Field	Value
Publication number	US-10541136-B2
Application number	US-201715825398-A
Country	US
Kind code	B2
Filing date	Nov 29, 2017
Priority date	Nov 29, 2016
Publication date	Jan 21, 2020
Grant date	Jan 21, 2020

Abstract

In one aspect a method of fabricating an n-doped strained germanium (Ge) film is disclosed, which includes depositing a strained Ge film on an underlying substrate, implanting at least one electron-donating dopant in the Ge film, and exposing the implanted Ge film to one or more laser pulses having a pulsewidth in a range of about 1 ns to about 100 ms so as to generate a substantially crystalline strained Ge film. In some embodiments, the pulses can cause melting followed by substantial recrystallization of at least a portion of the implanted Ge film. In some embodiments, the resultant Ge film can have a thickness in a range of about 10 nm to about 1 microns.

First claim

What is claimed is:

1. A semiconductor structure, comprising:
a support substrate,
an n-doped strained Ge film disposed on said substrate,
wherein said Ge film has an active donor concentration of an electron-donating dopant of at least about 1×10 20 cm −3 for at least one depth less than about 200 nm and exhibits a substantially crystalline structure, and
wherein said n-doped strained Ge film further comprises at least another dopant that is capable of passivating vacancies in said Ge film.

2. The semiconductor structure of claim 1 , wherein said active donor concentration is in a range of about 1×10 20 cm −3 to about 2×10 20 cm −3 .

3. The semiconductor structure of claim 1 , wherein said support substrate is a semiconductor.

4. The semiconductor structure of claim 1 , wherein said support substrate is any of silicon, silicon dioxide and GaAs.

5. The semiconductor structure of claim 1 , wherein said electron-donating dopant comprises any of antimony, phosphorus and arsenic.

6. The semiconductor structure of claim 1 , wherein said at least another dopant comprises any of fluorine, nitrogen and carbon.

7. The semiconductor structure of claim 1 , wherein said Ge film has a thickness in a range of about 10 nm to about 1 micron.

8. The semiconductor structure of claim 1 , wherein said Ge film exhibits a strain in a range of about 0.1% to about 3%.

9. A semiconductor structure, comprising:
a support substrate,
an n-doped strained Ge film disposed on the substrate, wherein said Ge film exhibits a substantially crystalline structure, and
wherein the Ge film comprises two or more dopants and exhibits an active donor concentration of an electron-donating dopant of at least about 5×10 19 cm −3 ,
wherein at least one dopant of the two or more dopants is capable of passivating vacancies present in the Ge film when implanted therein.

10. The semiconductor structure of claim 9 , wherein the at least one dopant is fluorine.

Assignees

• Harvard College

Inventors

• Mazur Eric
• Aziz Michael J
• Gandhi Hemant
• Pastor David

Classifications

• H10P14/3442

  N-type · CPC title

• H10P14/2922

  being non-crystalline insulating materials, e.g. glass or polymers · CPC title

• H10P14/2911

  Arsenides · CPC title

• H10P95/90

  Thermal treatments, e.g. annealing or sintering · CPC title

• H10P72/0436

  mainly by radiation · CPC title