US 8,785,865 B2 · Semiconductor detector for two-dimensionally detecting radiation positions and method for two-dimensionally detecting radiation positions using the same

Abstract

A semiconductor 2D position detector for two-dimensionally detecting positions of radiation is a Schottky diode comprising: a semiconductor substrate 2; a first to an nth (n is an integer of 2 or higher) stripe electrodes 3 arranged on the surface 2A of the semiconductor substrate 2 at given intervals in the X direction and in parallel to the Y direction; and an electrode 15 formed on the rear surface 2B of the semiconductor substrate 2. The top and the bottom ends of each of the stripe electrodes 3 are sequentially connected via a resistor 4, 5, and signals V1 to V4 output from the radiation 16 applied to the semiconductor substrate 2 are obtained from each of the both ends of the first and the nth stripe electrodes placed far left and right.

A semiconductor 2D position detector for two-dimensionally detecting the position of radiation, characterized in that it comprises:

a semiconductor substrate;
a first to an nth (n is an integer of 2 or higher) stripe electrodes arranged on the surface of the semiconductor substrate in the X direction at given intervals and in parallel to the Y direction;
a plurality of resistors connecting the top ends of the first to the nth stripe electrodes adjacent to each other;
a plurality of resistors connecting the bottom ends of the first to the nth stripe electrodes adjacent to each other;
a first terminal for signal output connected to the bottom end of the first stripe electrode via a resistor;
a second terminal for signal output connected to the bottom end of the nth stripe electrode via a resistor;
a third terminal for signal output connected to the top end of the nth stripe electrode via a resistor;
a fourth terminal for signal output connected to the top end of the first stripe electrode via a resistor;
an electrode disposed on the rear surface of the semiconductor substrate;
and
an operation part for calculating the position of radiation using output signals obtained from the first to the fourth terminals for signal output as a result of application of radiation to given points on the semiconductor substrate, wherein
the first to the nth stripe electrodes are separated from each other along the Y direction by grooves,
the ratio of the resistance value of each of the stripe electrodes and that of the resistors connecting the top ends and/or bottom ends of the stripe electrodes adjacent to each other falls within the 10:1 to 100:1 range,
the operation part is calculating the temporary positional coordinates (Xi, Yj) of the radiation using the formulae (1) and (2) as shown below by obtaining output voltages V1, V2, V3, V4 using the output signals from the first to the fourth terminals for signal output and furthermore calculates the detected positional coordinates (Xp, Yq) of the radiation using the formulae (3) and (4) as shown below based on the temporary positional coordinates (Xi, Yj), and
the resistance ratio is set to the value allowing the distortion of the temporary positional coordinates (Xi, Yj) in the Y direction to be suppressed and the detected current to be discriminated from noise current:
[
Formula
⁢
⁢
1
]
⁢
X
i
=
(
V
2
+
V
3
)
-
(
V
1
+
V
4
)
V
1
+
V
2
+
V
3
+
V
4
(
1
)
[
Formula
⁢
⁢
2
]
⁢
Y
j
=
(
V
4
+
V
3
)
-
(
V
1
+
V
2
)
V
1
+
V
2
+
V
3
+
V
4
(
2
)
[
Formula
⁢
⁢
3
]
⁢
X
p
=
f
⁡
(
X
i
,
Y
j
)
(
3
)
[
Formula
⁢
⁢
4
]
⁢
Y
q
=
g
⁡
(
X
i
,
Y
j
)
(
4
)
where, the functions f (Xi, Yj) and g (Xi, Yj) of the formulae (3) and (4) as shown above are found according to the following procedure:
The radiation spots on the stripe electrodes of the semiconductor 2D position detector are irradiated in the Y direction at given intervals, the temporary positional coordinate of each irradiation position is calculated. Then assuming a corrective function for the positional coordinate of each irradiation position and the temporary positional coordinate of each irradiation position after calculating the temporary positional coordinate of each irradiation position, the above functions f (Xi, Yj) and g (Xi, Yj) are found by fitting as a function for reproducing the positional coordinate of each radiation irradiation position.

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Semiconductor detector for two-dimensionally detecting radiation positions and method for two-dimensionally detecting radiation positions using the same

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Semiconductor detector for two-dimensionally detecting radiation positions and method for two-dimensionally detecting radiation positions using the same

Life of this patent

Abstract

Claims11