Semiconductor Device with Cavity Radiation Barrier for Cross-Talk Reduction

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Solution Overview

Problem

Existing semiconductor devices with radiation emitters and photosensors face challenges in preventing optical cross-talk, which affects their performance and efficiency.

Innovation Solution

A semiconductor device configuration featuring a semiconductor substrate with a photosensor integrated at the main surface, a radiation emitter mounted above, and a cover with a cavity that includes a radiation barrier to shield against cross-talk, along with passive optical components and a dielectric layer for electrical interconnections, is developed. The cover is partially transmissive and comprises a semiconductor layer on a glass wafer with cavities to accommodate the emitter and photosensor, reducing optical interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the emitter and photosensor are placed close together in a compact configuration, then the device size is reduced, but optical cross-talk between the emitter and photosensor increases

Engineering Contradiction:
Improvedevice sizeVSAvoidoptical cross-talk
Core Design Contradiction:
Volume of moving objectVSObject-affected harmful factors

Solution Approach 1:

The cover is segmented into multiple cavities, with each cavity housing either an emitter or a photosensor. This spatial segmentation prevents direct optical coupling between emitters and photosensors, thereby reducing cross-talk while maintaining a compact overall device structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cover acts as an intermediary structure between the emitter and photosensor. By introducing this intermediate component with cavity structures, the direct optical path is blocked, and cross-talk is reduced while still allowing the device to maintain a compact form factor.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If a radiation barrier is added to shield against cross-talk, then optical cross-talk is reduced, but the device complexity increases

Engineering Contradiction:
Improveoptical cross-talkVSAvoidstructure complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The radiation barrier function is merged with the cover structure itself. The cover is designed with integrated cavity features that simultaneously provide mechanical housing and optical shielding, eliminating the need for separate barrier components and reducing overall device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The cover serves multiple functions: it provides mechanical protection, defines the optical path through its cavity structure, and acts as a radiation barrier to prevent cross-talk. This multi-functionality reduces the need for additional components and simplifies the overall device architecture.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Volume of moving object

If multiple components are integrated in a compact arrangement, then the device becomes more compact, but manufacturing precision requirements increase

Engineering Contradiction:
Improvedevice sizeVSAvoidalignment precision
Core Design Contradiction:
Volume of moving objectVSManufacturing precision

Solution Approach 1:

The cover with its cavity structures is prepared in advance as a pre-assembled component. This preliminary preparation establishes fixed reference geometries that guide the subsequent placement of emitters and photosensors, thereby reducing the alignment precision requirements during final assembly.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The cavity structures in the cover utilize the vertical dimension to separate emitters and photosensors spatially. By arranging components in three-dimensional space rather than a flat two-dimensional plane, the design provides natural alignment references and reduces the stringency of planar alignment requirements.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 configuration effectively inhibits optical cross-talk between the emitter and photosensor, enhancing the compactness and performance of the semiconductor device while maintaining compatibility with standard CMOS processes.

Implementation Method 1

The radiation barrier is arranged laterally to the cavity and shields electromagnetic radiation, in particular visible light and/or infrared radiation

Methodology Applied
Scientific EffectElectromagnetic radiation shielding: Absorption (EM radiation)

Implementation Method 2

a photosensor integrated in the substrate at a main surface... The photosensor may be provided for a detection of radiation in any specified range of wavelengths, which is not restricted to visible light

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Implementation Method 3

an emitter of radiation like a light-emitting diode... An opaque element can be applied to reduce optical cross-talk between the emitter and the photosensor

Methodology Applied
Scientific EffectLight-emitting diode effect: Light Emitting Diode

Data Source

PatentEP2955759B1Semiconductor device comprising an emitter of radiation and a photosensor and appertaining production method
Publication Date: 2018.09.05 AUSTRIAMICROSYSTEMS AG
  • EP2955759B1 patent drawingFigure 1~2
  • EP2955759B1 patent drawingFigure 3~4
  • EP2955759B1 patent drawingFigure 5~6

AI summary

The semiconductor device comprises a semiconductor substrate (1), a photosensor (2) integrated in the substrate (1) at a main surface (10), an emitter (12) of radiation mounted above the main surface (10), and a cover (6), which is at least partially transmissive for the radiation, arranged above the main surface (10). The cover (6) comprises a cavity (7), and the emitter (12) is arranged in the cavity (7). A radiation barrier (9) can be provided on a lateral surface of the cavity (7) to inhibit cross-talk between the emitter (12) and the photosensor (2).