Amorphous silicon ionizing particle detectors
First Claim
Patent Images
1. A particle detector having a body portion for detecting high energy ionizing particles moving in a path toward said detector where, upon penetration into said detector body portion, form electron-hole pairs and comprising:
- a substrate,first electrode means formed on said substrate,an a--Si;
H film deposited on said first electrode,said a--Si;
H film comprises three monolithic, contiguous regions consecutively comprising an a--Si region doped to be a first conductivity type, an intrinsic region of a--Si and an a--Si region doped to be a second conductivity type,second electrode means formed over said a--Si;
H film,means to increase the sensitivity to a level sufficient to detect single ionizing particles as they individually impact said detector body portion by increasing the collection efficiency of said a--Si;
H film intrinsic region to have a low trap density below 1×
1016 cm-3 ev-1 with a large film thickness above 1 μ
m and operative at voltages above 50 volts per μ
m, andmeans to collect said electron-hole pairs and indicate the number and energy level of said ionizing particles.
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Abstract
Amorphous silicon ionizing particle detectors having a hydrogenated amorphous silicon (a--Si:H) thin film deposited via plasma assisted chemical vapor deposition techniques are utilized to detect the presence, position and counting of high energy ionizing particles, such as electrons, x-rays, alpha particles, beta particles and gamma radiation.
86 Citations
17 Claims
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1. A particle detector having a body portion for detecting high energy ionizing particles moving in a path toward said detector where, upon penetration into said detector body portion, form electron-hole pairs and comprising:
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a substrate, first electrode means formed on said substrate, an a--Si;
H film deposited on said first electrode,said a--Si;
H film comprises three monolithic, contiguous regions consecutively comprising an a--Si region doped to be a first conductivity type, an intrinsic region of a--Si and an a--Si region doped to be a second conductivity type,second electrode means formed over said a--Si;
H film,means to increase the sensitivity to a level sufficient to detect single ionizing particles as they individually impact said detector body portion by increasing the collection efficiency of said a--Si;
H film intrinsic region to have a low trap density below 1×
1016 cm-3 ev-1 with a large film thickness above 1 μ
m and operative at voltages above 50 volts per μ
m, andmeans to collect said electron-hole pairs and indicate the number and energy level of said ionizing particles. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method for improving the detection of high energy ionizing particles which comprises the steps of:
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providing a detector body portion of a--Si;
H film, said film being sandwiched between a pair of electrodes,increasing the sensitivity level of said a--Si;
H film sufficient to detect single ionizing particles as they individually impact said detector body portion by increasing the collection efficiency of said a--Si;
H film to have a low trap density below 1×
1016 cm-3 ev-1 with a large film thickness above 1 μ
m and operative at voltages above 50 volts per μ
m,placing the detector in a path of ionizing particle radiation wherein said radiation is separated into electron-hole pairs as said radiation penetrates into said detector body portion, separating and collecting said electron-hole pairs, detecting said collected electron-hole pairs by measuring the output current response upon collection thereof wherein each detected current output pulse is representative of a single electron-hole pair, and counting said current output pulses. - View Dependent Claims (8, 9, 10, 11, 12)
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13. A single particle detector having a body portion for detecting high energy ionizing particles moving in a path toward said detector, said detector comprising a combination of contiguous films of a--Si:
- H film and CsI, said CsI film causing said particles to be converted into photons, said a--Si film sensitive to said photons and separating them into electron-hole pairs, means to collect said electron-hole pairs indicative of the number and energy level of said ionizing particles.
- View Dependent Claims (14)
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15. A single particle detector having a body portion for detecting high energy ionizing particles moving in a path toward said detector where, upon penetration into said detector body portion, form electron-hole pairs,
means to separate said electron-hole pairs and collect the separated electrons and holes indicative of the number and energy level of said particles, a--Si: - H film comprising said body portion and having at least, in part, a planar surface for receiving said particles and generating said electron-hole pairs,
means to support said film planar surface at an angle transverse to said particle path to increase the path length of particle penetration in said film and to permit the unincumbered separation and collection of said electron-hole pairs without interference in the collection of other separated electrons and holes so as to increase the sensitivity level of particle detection. - View Dependent Claims (16, 17)
- H film comprising said body portion and having at least, in part, a planar surface for receiving said particles and generating said electron-hole pairs,
Specification