Spiral biasing adaptor for use in Si drift detectors and Si drift detector arrays

Patent metadata

Field	Value
Publication number	US-9383452-B2
Application number	US-201214352538-A
Country	US
Kind code	B2
Filing date	Oct 24, 2012
Priority date	Oct 25, 2011
Publication date	Jul 5, 2016
Grant date	Jul 5, 2016

Abstract

A drift detector array, preferably a silicon drift detector (SDD) array, that uses a low current biasing adaptor is disclosed. The biasing adaptor is customizable for any desired geometry of the drift detector single cell with minimum drift time of carriers. The biasing adaptor has spiral shaped ion-implants that generate the desired voltage profile. The biasing adaptor can be processed on the same wafer as the drift detector array and only one biasing adaptor chip/side is needed for one drift detector array to generate the voltage profiles on the front side and back side of the detector array.

First claim

The invention claimed is:

1. A method of detecting radiation, comprising,
detecting radiation by an array of drift detector cells;
reducing overheating and power consumption of the drift detector array during the detection by connecting the drift detector array to a spiral biasing adaptor (SBA) configured to function as a voltage divider.

2. The method of claim 1 , wherein a design of the spiral biasing adaptor (SBA) satisfies the equation
ρ s Iαr=E ( r ) W ( r ) p ( r )

where ρ s is an implant sheet resistance, I is a current, αr is a length of each turn of the spiral, E(r) is a surface electric field at a radius r, W(r) is a spiral width of a spiral arm at radius r, and p(r) is a spiral pitch at radius r.

3. A drift detector comprising a Si drift detector (SDD) cell connected to a spiral biasing adaptor (SBA) configured to function as a voltage divider wherein a design of the spiral biasing adaptor satisfies the equation
ρ s Iαr=E ( r ) W ( r ) p ( r )

wherein ρ s is an implant sheet resistance, I is a current, αr is a length of each turn of the spiral, E(r)is a surface electric field at a radius r, W(r) is a spiral width of a spiral arm at radius r, and p(r) is a spiral pitch at radius r, wherein the spiral pitch and the spiral width can both change with the radius, wherein the drift detector has a front side and a back side with a first electric field potential to the front side and a second electric field applied to the back side, wherein a negative electrical potential of a spiral in the SBA satisfies equation:

φ
⁡

(
r
)

=

∫

r
1

r

⁢

2
⁢
π
⁢

ⅆ
r

p
⁡

(
r
)

for a given spiral pitch p(r) at radius r, wherein the width of a spiral of the SBA satisfies equation:

W
⁡

(
r
)

=

ρ
s

⁢
Iar

E
⁡

(
r
)

⁢

p
⁡

(
r
)

wherein the electric field E(r) on the front side of the SBA and the SDD cell is defined by

E
⁡

(
r
)

=

2
⁢

V
fd

⁢

E

dr
,
r

(

1
-
γ

)

2

⁢

[

(

1
-
γ

)

⁢



V
B



+

(

1
+
γ

)

⁢

V
fd

(

1
-
γ

)

2

-



V

E
⁢

⁢
1



]

2

-

4
⁢

V
fd

Assignees

• Brookhaven Science Ass Llc

Inventors

• Li Zheng
• Chen Wei

Classifications

• G01T1/2928 Primary

  using solid state detectors · CPC title

• G01T1/02 Primary

  Dosimeters (G01T1/15 takes precedence) · CPC title