Silicon Light Emitting Device Lateral Isolation Removal

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing light emitting devices fabricated using semiconductor materials like silicon face challenges due to isolation techniques that inhibit punch-through and reach-through modes, leading to reduced electroluminescence efficiency and light transmission issues.

Innovation Solution

A light emitting device is designed with a substrate having laterally extending links between doped islands, eliminating isolation barriers to facilitate punch-through and reach-through modes, and a terminal arrangement to apply reverse bias, enhancing light transmission and efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If isolation barriers are formed using lateral device isolation techniques (LOCOS or STI) to laterally isolate doped implanted regions, then device isolation and manufacturing precision are improved, but light transmission is inhibited and electroluminescence efficiency is reduced

Engineering Contradiction:
Improvelateral device isolationVSAvoidlight inhibition
Core Design Contradiction:
Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The patent removes the isolation barrier between adjacent doped regions by not forming field oxide or trenches in those specific areas. This extraction of the isolation structure allows light to transmit through the substrate without being blocked by the isolation barriers, while maintaining manufacturing precision through selective masking during the fabrication process.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent applies different structural qualities to different regions: isolation barriers are formed in some areas to provide lateral isolation, while deliberately omitting isolation barriers in specific regions between doped implanted regions to allow light transmission. This local differentiation resolves the contradiction by optimizing each region for its specific function.

Inventive Principle:
Principle #3Local quality

2Reliability

If gate structures are formed between implanted regions to control device operation, then device control and reliability are improved, but light transmission is inhibited

Engineering Contradiction:
Improvedevice controlVSAvoidlight transmission inhibition
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent removes gate structures from specific regions where light transmission is desired. By not forming gate electrodes and associated insulation layers in those areas, light can pass through without being blocked, while gate structures are retained in other regions where device control is necessary.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent segments the device structure into functional zones: regions with gate structures for device control and regions without gate structures for light transmission. This segmentation allows both functions to coexist by spatially separating their requirements.

Inventive Principle:
Principle #1Segmentation

3Productivity

If sandwiched configuration of immediately adjacent doped regions is used to form light emitting devices, then device integration and productivity are improved, but isolation barriers inhibit punch-through and reach-through modes reducing electroluminescence efficiency

Engineering Contradiction:
Improvedevice integrationVSAvoidelectroluminescence efficiency
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent extracts isolation barriers from the sandwiched configuration between immediately adjacent doped regions. By removing field oxide or trench isolation in these specific areas, punch-through and reach-through modes can occur, enabling efficient electroluminescence while maintaining the integrated sandwiched structure for high productivity.

Inventive Principle:
Principle #2Taking out (Extraction)

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

The solution improves external quantum efficiency by eliminating light inhibition structures, allowing for better carrier injection and distribution of electric fields, thereby increasing the chances of successful punch-through and reach-through operations, enhancing electroluminescence effects.

Implementation Method 1

enhancing electroluminescence effects

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Implementation Method 2

allowing for better carrier injection and distribution of electric fields, thereby increasing the chances of successful punch-through and reach-through operations

Methodology Applied
Scientific EffectPunch-through effect:

Implementation Method 3

allowing for better carrier injection and distribution of electric fields, thereby increasing the chances of successful punch-through and reach-through operations

Methodology Applied
Scientific EffectReach-through effect:

Data Source

PatentEP2526571B1Silicon light emitting device and method of fabricating same
Publication Date: 2019.05.01 INSIAVA (PTY) LTD
  • EP2526571B1 patent drawingFigure 1~2
  • EP2526571B1 patent drawingFigure 3
  • EP2526571B1 patent drawingFigure 4

AI summary

A light emitting device (10) comprises a body (11) comprising a substrate (12) of a p-type semiconductor material. The substrate has an upper surface (14) and having formed therein on one side of the upper surface and according to a bulk semiconductor fabrication process utilizing lateral active area isolation techniques: a first n+-type island (16) to form a first junction (24) between the first island and the substrate; and a second n+ - type island (18) spaced laterally from the first island (16). The substrate provides a laterally extending link (20) between the islands having an upper surface. The upper surface of the link, an upper surface of the island (16) and an upper surface of the island (18) collectively form a planar interface (21) between the body (11) and an isolation layer (19) of the device. The device comprises a terminal arrangement to apply a reverse bias to the first junction, to cause the device to emit light. The device is configured to facilitate the transmission of the emitted light.