ZERO-BIAS PHOTOGATE PHOTODETECTOR

Abstract

A photogate photodetector (10) comprising: a first electrode consisting of amorphous germanium (12) covered with transition metal species having a thickness in the range of 0.1-5 nm (11); a second electrode (14) which is an n-type silicon layer; and a dielectric layer (13) arranged between the first and second electrode; with a depletion layer (15) formed in the n-type silicon layer (14) at the interface to the dielectric layer (13).

Claims

1. A photogate photodetector (10) comprising: a first electrode consisting of amorphous germanium (12) covered with transition metal species having a thickness in the range of 0.1-5 nm (11); a second electrode (14) which is an n-type silicon layer; and a dielectric layer (13) arranged between the first and second electrode; with a depletion layer (15) formed in the n-type silicon layer (14) at the interface to the dielectric layer (13).

2. The photogate photodetector according to claim 1, wherein the metal specie is selected from Ni, Cr, Nb, Mo, Au, Pt, Fe, Cu, Ta, V, Co and W.

3. The photogate photodetector according to claim 1, wherein the metal specie consists of a metal alloy, wherein the metal alloy comprises at least two of Ni, Cr, Nb, Mo, Au, Pt, Fe, Cu, Ta, V, Co and W.

4. The photogate photodetector according to any one of the preceding claims, wherein a thickness of the amorphous germanium layer is in the range of 5 nm to 200 nm.

5. The photogate photodetector according to any one of the preceding claims, wherein a thickness of the dielectric layer is in the range of 5 nm to 100 nm.

6. The photogate photodetector according to any one of the preceding claims, wherein the dielectric layer is selected from Al2O3, SiO2, Hf2O, HfSiO, HfSiON, SiN or AlN.

7. The photogate photodetector according to any one of the preceding claims, wherein the dielectric layer comprises at least two of Al2O3, SiO2, Hf2O, HfSiO, HfSiON, SiN or AlN.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] With reference to the appended drawing showing an example embodiment of the present invention, below follows a more detailed description of the various aspect of the invention.

[0014] FIG. 1 schematically illustrates a zero-bias photogate-photodetector according to an embodiment of the invention.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0015] The present invention will now be described more afterward in this document with reference to the accompanying drawing.

[0016] FIG. 1 schematically shows a zero-bias photogate photodetector 10 comprising: a first electrode consisting of amorphous germanium 12 covered with a few atomic layers of transition metal species 11; a second electrode 14 which is an n-type silicon; a dielectric layer 13 arranged between the first and second electrode. A depletion layer 15 is formed in the n-type silicon layer 14 at the interface to the dielectric layer 13.

[0017] The material used to form thin metal layer 11 are selected from transition metal Ni, Cr, Nb, Mo, Au, Pt, Fe, Cu, Ta, V, Co and W. Accordingly, it is possible to forma metal alloy comprising two or more metals.

[0018] The amorphous germanium 12 may have a thickness in the range of 5-200 nm, the dielectric 13 may have a thickness in the range of 5-100 nm and the thin metal layer 11 may have a thickness in the range of 0.1-5 nm.