Recessed CdZnTe Radiation Detector for High-Resistivity Charge Collection
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Solution Overview
Problem
Current radiation detectors based on semiconductor materials like CdZnTe face challenges in achieving optimal performance and efficiency, particularly in forming high-quality semiconductor single crystals with distinct compositions for enhanced radiation detection capabilities.
Innovation Solution
A method involving the formation of a recess in a substrate for a semiconductor single crystal with a different composition, accompanied by a heavily doped semiconductor region and a passivation layer, to create a radiation detector that effectively absorbs radiation and generates charge carriers, with the heavily doped region extending from the interface to the substrate surface and an electrical contact embedded in the passivation layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a semiconductor single crystal with different composition is formed in a recess, then the radiation detection capability and signal-to-noise ratio are improved, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The detector is divided into distinct regions: a substrate, a recess containing a semiconductor single crystal with different composition, and a heavily doped semiconductor region. This segmentation allows each region to perform its specific function optimally, improving signal-to-noise ratio while managing complexity through functional specialization.
Solution Approach 2:
The semiconductor single crystal within the recess has a different composition from the substrate, creating local quality variation. This compositional difference optimizes radiation detection in the recess region while the substrate provides structural support, resolving the contradiction between performance and complexity.
2Reliability
If a heavily doped semiconductor region is formed extending from the interface to the substrate surface, then the electrical contact and charge carrier collection are improved, but the manufacturing precision requirements increase
Solution Approach 1:
The heavily doped semiconductor region is formed in advance, extending from the interface between the single crystal and substrate to the substrate surface. This preliminary action ensures proper electrical contact and charge carrier collection pathways are established before final device assembly, improving reliability while managing manufacturing precision requirements.
3Reliability
If the semiconductor single crystal has a larger band gap, then the maximum achievable electrical resistivity increases, but the manufacturing complexity and process difficulty increase
Solution Approach 1:
The semiconductor single crystal is designed with a larger band gap than the substrate material, changing the electrical parameter to achieve higher maximum achievable electrical resistivity. This parameter change improves detector performance while the recess structure manages the manufacturing complexity associated with growing such crystals.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances the radiation detector's ability to absorb radiation particles, generating charge carriers efficiently, thereby improving the signal-to-noise ratio and achieving high resistivity, making it suitable for various applications including medical and industrial imaging.
Implementation Method 1
a radiation detector of this type may have a semiconductor layer that absorbs the radiation and generate charge carriers (e.g., electrons and holes)
Implementation Method 2
the heavily doped region is in electrical contact with the semiconductor single crystal and embedded in a portion of intrinsic semiconductor of the substrate
Data Source
AI summary
Disclosed herein are a radiation detector and a method of making it. The radiation detector is configured to absorb radiation particles incident on a semiconductor single crystal of the radiation detector and to generate charge carriers. The semiconductor single crystal may be a CdZnTe single crystal or a CdTe single crystal. The method may comprise forming a recess into a substrate of semiconductor; forming a semiconductor single crystal in the recess; and forming a heavily doped semiconductor region in the substrate. The semiconductor single crystal has a different composition from the substrate. The heavily doped region is in electrical contact with the semiconductor single crystal and embedded in a portion of intrinsic semiconductor of the substrate.