Optoelectronic Semiconductor Chip ESD Protection via V-Defect Microdiodes

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Solution Overview

Problem

Optoelectronic semiconductor chips, particularly light-emitting diodes, are vulnerable to electrostatic discharge (ESD) voltage pulses, which can cause damage by concentrating electrical charge through weak leakage paths, leading to destruction.

Innovation Solution

Incorporating a first semiconductor layer sequence with microdiodes formed by V-defects, which act as ESD protection, ensuring that ESD voltage pulses are dissipated evenly across a large area, preventing local destruction by distributing the charge through numerous microdiodes with similar electrical properties and breakdown behaviors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional semiconductor chip structure is used, then manufacturing is simpler, but ESD resistance is poor due to concentrated charge through weak leakage paths

Engineering Contradiction:
ImproveESD resistanceVSAvoidsemiconductor layer sequence structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The semiconductor chip is segmented into multiple functional layers: a first semiconductor layer sequence containing numerous microdiodes arranged in a grid pattern, and a second semiconductor layer sequence containing the active region. This segmentation distributes ESD charge across many microdiodes rather than concentrating it through single leakage paths, thereby improving ESD resistance while maintaining manageable structural complexity through systematic layering.

Inventive Principle:
Principle #1Segmentation

2Reliability

If microdiodes are added for ESD protection, then ESD resistance improves, but manufacturing complexity increases

Engineering Contradiction:
ImproveESD resistanceVSAvoidmanufacturing process
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The microdiodes and active region are merged into a unified semiconductor structure grown in sequence on a common substrate. The first semiconductor layer sequence with microdiodes is grown first, followed by the second semiconductor layer sequence with the active region. This merging allows both ESD protection and light emission functions to be integrated in a single manufacturing process, reducing the need for separate assembly steps and improving ease of manufacture despite the added functionality.

Inventive Principle:
Principle #5Merging (Combining)

3Object-affected harmful factors

If charge is concentrated through leakage paths, then ESD voltage pulses cause damage, but distributing charge requires complex microdiode structures

Engineering Contradiction:
ImproveESD damage protectionVSAvoidmicrodiode arrangement
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

Different regions of the semiconductor chip are assigned different local qualities: the first semiconductor layer sequence contains microdiodes with specific electrical properties optimized for ESD protection, while the second semiconductor layer sequence contains the active region with properties optimized for light emission. This local differentiation allows the microdiode grid to handle ESD charges effectively without compromising the performance of the active region, achieving ESD damage protection with organized rather than random structural complexity.

Inventive Principle:
Principle #3Local quality

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 significantly enhances the ESD resistance of optoelectronic semiconductor chips, allowing them to withstand ESD voltages of at least 1 kV, typically 2 kV, without damaging the active radiation-generating area, by ensuring a quasi-two-dimensional breakdown distribution across the chip's cross-sectional area.

Implementation Method 1

The microdiodes exhibit a breakdown voltage in their reverse bias. During operation of the optoelectronic semiconductor chip, the microdiodes are designed such that they are not destroyed when the breakdown voltage is exceeded

Methodology Applied
Scientific EffectBreakdown voltage: Avalanche Breakdown

Data Source

PatentEP3240049B1Method for manufacturing an optoelectronic semiconductor chip and optoelectronic semiconductor chip
Publication Date: 2023.04.12 OSRAM OPTO SEMICON GMBH & CO OHG
  • EP3240049B1 patent drawingFigure 1A~1C
  • EP3240049B1 patent drawingFigure 2
  • EP3240049B1 patent drawingFigure 3A~3C

AI summary

A method for manufacturing an optoelectronic semiconductor chip (100) is specified, comprising the steps: - providing a growth substrate (7), - epitaxial deposition of a first semiconductor layer sequence (1), - epitaxial deposition of a second semiconductor layer sequence (2) onto the first semiconductor layer sequence (1), wherein - the first semiconductor layer sequence (1) comprises an ESD layer (9) which is deposited at a growth temperature at which V-defects occur in high density in the ESD layer (9), and - the second semiconductor layer sequence (2) comprises an active region (12).