Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
45 words
An infra red sensitive photo diode comprising a piece of Cd x Hg 1-x Te(1, 11, 20) and a piece of CdTe (8, 12, 27) forming a p-n junction with terminals (5, 6, 15, 16, 25, 26) connected to the p and n type materials.
Claim 2
Dependent Claim
45 words
An infra red sensitive photo diode comprising a piece of Cd x Hg 1-x Te(1, 11, 20) and a piece of CdTe (8, 12, 27) forming a p-n junction with terminals (5, 6, 15, 16, 25, 26) connected to the p and n type materials.
Claim 3
Dependent Claim
19 words
The photo diode of claim 1 wherein there is a graded heterostructure (7, 19, 24) between the two materials.
Claim 4
Dependent Claim
33 words
The photo diode of claim 1 wherein regions (2, 13, 22) of Cd x Hg 1-x Te away from the p-n junction (7, 17, 24) are passivated by a layer of semi-insulating CdTe.
Claim 5
Dependent Claim
42 words
The photo diode of claim 3 formed into an array of photo diodes on the same piece of Cd x Hg 1-x Te with regions (8, 12, 27) of doped CdTe separated by a passivating layer of semi-insulating CdTe (2, 13, 22).
Claim 6
Dependent Claim
29 words
The photo diode of claim 1 wherein the Cd x Hg 1-x Te ( 1, 11, 20 ) is p- type and the CdTe (8, 12, 27) is n-type.
Claim 7
Dependent Claim
30 words
The photo diode of claim 5 wherein the n-type CdTe (8, 27) is formed by diffusion of a group IIIa or VII donor dopant into a semi-insulating layer of CdTe.
Claim 8
Dependent Claim
11 words
The photo diode of claim 6 wherein the dopant is In.
Claim 9
Dependent Claim
26 words
The photo diode of claim 5 wherein the n-type CdTe (12) is formed by molecular beam epitaxial growth using beams of Cd, Te and a dopant.
Claim 10
Dependent Claim
36 words
The photo diode of claim 2 wherein the graded hetero junction (7, 17, 24) is formed by diffusion between the Cd x Hg 1-x Te and CdTe materials on heating in the range 70 to 120°C.
Claim 11
Dependent Claim
40 words
The photo diode of claim 5 wherein x is in the range 0.2 to 0.3 inclusive and the acceptor concentration in the Cd x Hg 1-x Te material in the range 1 to 5 x 10 16 cm -3 .
Claim 12
Dependent Claim
29 words
The photo diode of claim 5 wherein n-type region of the CdTe are doped to give the number of electrons, n > 5 x 10 16 cm -3 .
Claim 13
Dependent Claim
19 words
The photo diode of claim 1 wherein the Cd Hg Te is n-type and the CdTe is p type.
Claim 14
Dependent Claim
28 words
The photo diode of claim 3 wherein the CdTe is a layer (2, 8, 12, 13, 22, 27) having a thickness in the range 0.2 to 1 µm.
Claim 15
Dependent Claim
98 words
The photo diode of claim 1 formed into an array comprising a substrate (1, 11, 20) of p-type Cd x Hg 1-x Te having a surface passivated with a layer (2, 8, 12, 13, 22, 27) of semi-insulating CdTe, regions (8, 12, 27) of n-type CdTe formed by In selectively deposited (4, 23) on the CdTe and diffused into the CdTe by heating in the range 70° to 120°C each region of n-type CdTe providing a photo diode, and electrical contacts (5, 6, 25, 26) associated with each, n-type region (8, 27) and with the substrate (1, 20).