Trap-Rich Substrate Structure for BiCMOS Leakage Isolation

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Solution Overview

Problem

BiCMOS integration on high resistivity semiconductor substrates faces compatibility issues among different devices, leading to low yields and device-to-device leakage, which are not effectively addressed by existing technologies.

Innovation Solution

A semiconductor structure with a high resistivity substrate, a buried insulator layer, and a low resistivity region floating below an active device, utilizing semiconductor-on-insulator technology and implantation processes to create trap rich and low resistivity regions, which are fabricated using photolithographic and etching techniques to maintain high NPN yield and reduce leakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If BiCMOS integration is performed on high resistivity semiconductor substrates, then device performance is improved, but device compatibility and manufacturing yield deteriorate due to incompatible parameters among different devices

Engineering Contradiction:
Improvedevice performanceVSAvoidmanufacturing yield
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies local quality by creating distinct regions within the semiconductor substrate with different resistivity characteristics. High resistivity regions are formed beneath certain devices to maintain performance, while low resistivity regions are created beneath other devices to ensure compatibility and yield. This spatial differentiation of electrical properties allows different device types to coexist on the same substrate without parameter conflicts

Inventive Principle:
Principle #3Local quality

2Reliability

If different parameters are used for different devices on the same substrate, then device performance is optimized, but device-to-device leakage increases

Engineering Contradiction:
Improvedevice performanceVSAvoiddevice-to-device leakage
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent segments the semiconductor substrate into isolated regions with different electrical characteristics. By dividing the substrate into high resistivity and low resistivity zones separated by isolation structures, it prevents electrical interaction between devices requiring different parameters, thereby eliminating the leakage pathway that would otherwise result from parameter incompatibility

Inventive Principle:
Principle #1Segmentation

3Reliability

If high resistivity substrate is used, then certain device performance is improved, but integration compatibility among different devices deteriorates

Engineering Contradiction:
Improvedevice performanceVSAvoidintegration compatibility
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent implements local quality by providing high resistivity substrate regions specifically where needed for optimal device performance, while introducing low resistivity regions in areas requiring better electrical compatibility for integration. This localized differentiation allows the substrate to simultaneously support both high-performance devices and compatible device integration

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

The solution maintains high NPN yield, reduces device-to-device leakage, and provides radiation hardening for FET devices while preserving BEOL passive device and RF FET performance, enhancing the reliability of integrated circuits.

Implementation Method 1

low resistivity region floating in the high resistivity semiconductor substrate

Methodology Applied
Scientific EffectElectrical resistivity: Electrical Resistance

Implementation Method 2

trap rich regions (high resistivity regions)

Methodology Applied
Scientific EffectCharge trapping: Absorption (physical)

Data Source

PatentEP4369385A1Integrated structure with trap rich regions and low resistivity regions
Publication Date: 2024.05.15 GLOBALFOUNDRIES US INC
  • EP4369385A1 patent drawingFigure 1
  • EP4369385A1 patent drawingFigure 2
  • EP4369385A1 patent drawing

AI summary

The present disclosure relates to semiconductor structures and, more particularly, to a substrate with trap rich and low resistivity regions and methods of manufacture. The structure includes: a high resistivity semiconductor substrate; an active device over the high resistivity semiconductor substrate; and a low resistivity region floating in the high resistivity semiconductor substrate and which is below the active device.