Recessed Semiconductor Single Crystal Radiation Detector

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Solution Overview

Problem

Current radiation detectors, particularly those based on semiconductor materials like CdZnTe, face challenges in optimizing the composition and structure for enhanced radiation absorption and charge carrier generation, leading to suboptimal performance in detecting various types of radiation such as X-rays and gamma rays.

Innovation Solution

The method involves forming a recess or through hole in a semiconductor substrate and filling it with a semiconductor single crystal of different composition, creating a p-n junction to enhance radiation absorption and charge carrier generation, and bonding an electronics layer to process the generated signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a semiconductor substrate with uniform composition is used, then the manufacturing process is simple, but the radiation absorption efficiency and charge carrier generation are suboptimal

Engineering Contradiction:
Improveradiation detection efficiencyVSAvoidsemiconductor structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies local quality by creating a composite semiconductor substrate with regions of different compositions. A first semiconductor region with higher zinc content (x1) is combined with a second semiconductor region with lower zinc content (x2), where each region has optimized properties for specific functions: one region prioritizes radiation absorption while the other optimizes charge carrier collection, thereby improving overall detection efficiency without requiring complete structural redesign

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent employs composite materials by integrating two different CdZnTe semiconductor compositions into a single substrate. The first semiconductor region contains CdZnTe with zinc molar concentration x1, while the second region contains CdZnTe with zinc molar concentration x2, creating a composite structure that leverages the complementary properties of different compositions to enhance both radiation absorption and electrical performance

Inventive Principle:
Principle #40Composite materials

2Reliability

If the zinc content in CdZnTe is increased to improve band gap and resistivity, then the signal-to-noise ratio improves, but the radiation absorption efficiency decreases

Engineering Contradiction:
Improvesignal-to-noise ratioVSAvoidradiation absorption capacity
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent resolves this contradiction by assigning different zinc concentrations to different spatial regions: the first semiconductor region with higher zinc content (x1) provides superior electrical resistivity and signal-to-noise ratio, while the second semiconductor region with lower zinc content (x2) maintains higher radiation absorption efficiency, allowing each region to optimize its local function without compromising the other

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent segments the semiconductor substrate into distinct functional regions based on zinc content. By dividing the uniform composition into multiple zones with graded or differentiated zinc concentrations, the patent enables simultaneous optimization of competing properties: high-zinc regions for electrical performance and low-zinc regions for absorption performance, with the segments working together as an integrated detector

Inventive Principle:
Principle #1Segmentation

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 improves the radiation detection efficiency by ensuring high absorbance and charge carrier generation, enabling better signal processing and enhancing the signal-to-noise ratio, thus improving the detector's performance across various applications.

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)

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Implementation Method 2

the first doped semiconductor region and the second doped semiconductor region form a p-n junction that separates the portion from the rest of the semiconductor substrate

Methodology Applied
Scientific Effectp-n junction separation: Diode

Data Source

PatentEP3948359B1Apparatuses for detecting radiation and their methods of making
Publication Date: 2023.12.27 SHENZHEN XPECTVISION TECH CO LTD
  • EP3948359B1 patent drawingFigure 1~2A
  • EP3948359B1 patent drawingFigure 2B~2C
  • EP3948359B1 patent drawingFigure 2D~2E

AI summary

An apparatus for detecting radiation and a method of making it. The method may comprise forming a recess (104) into a semiconductor substrate (102), wherein a portion (107) of the semiconductor substrate (102) extends into the recess (104) and is surrounded by the recess (104); forming a semiconductor single crystal (106) in the recess (104), the semiconductor single crystal (106) having a different composition from the semiconductor substrate (102); forming a first doped semiconductor region (108) in the semiconductor substrate (102); forming a second doped semiconductor region (109) in the semiconductor substrate (102); wherein the first doped semiconductor region (108) and the second doped semiconductor region (109) form a p-n junction that separates the portion (107) from the rest of the semiconductor substrate (102).