Polysilicon Contact Repair for Defect-Induced Leakage

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Solution Overview

Problem

The scaling down of semiconductor structures leads to defects in electrical contact structures, resulting in increased resistance and current leakage, which affects the quality, yield, and reliability of semiconductor products.

Innovation Solution

A method involving the implantation of a dopant material with a concentration of at least 10^15 atom/cm3 into regions of polysilicon material within trenches to repair defects, followed by annealing to form a doped polysilicon contact, reducing resistance and preventing current leakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If semiconductor structures are scaled down to meet application requirements, then device size is reduced, but defects in electrical contact structures increase leading to higher resistance and current leakage

Engineering Contradiction:

Improvedevice sizeVSAvoidelectrical contact quality

Core Design Contradiction:

Volume of moving objectVSReliability

Solution Approach 1:

The patent applies preliminary action by performing defect detection and repair processes before the electrical contact structure is fully formed and before final product testing. Specifically, the method detects defects in polysilicon material after deposition but before completing the contact structure fabrication, and repairs them through targeted dopant implantation. This early intervention prevents defective structures from proceeding to later stages, thereby maintaining reliability while enabling continued scaling.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements self-service through automated defect detection and repair systems that operate within the fabrication process itself. The system automatically identifies defective regions in the polysilicon material and applies localized dopant implantation without requiring manual intervention or external testing equipment. This self-correcting capability enables the manufacturing process to maintain high reliability autonomously during scaling operations.

Inventive Principle:

Principle #25Self-service

2Ease of manufacture

If conventional manufacturing processes are used for scaled-down structures, then manufacturing simplicity is maintained, but defect formation increases causing resistance increase and current leakage

Engineering Contradiction:

Improvemanufacturing process simplicityVSAvoidelectrical contact defect rate

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent applies local quality by transitioning from uniform processing to localized defect repair. Instead of modifying the entire manufacturing process or treating all polysilicon regions uniformly, the system identifies specific defective regions through detection and applies dopant implantation only to those localized areas. This targeted approach maintains overall process simplicity while achieving high precision in correcting defects, allowing conventional manufacturing to continue with minimal modifications.

Inventive Principle:

Principle #3Local quality

3Reliability

If dopant material is implanted into defective regions of polysilicon material, then resistance is reduced and current leakage is prevented, but additional manufacturing steps are required

Engineering Contradiction:

Improveelectrical contact performanceVSAvoidmanufacturing process steps

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The additional dopant implantation step is performed at an early stage in the fabrication process, after polysilicon deposition but before subsequent processing steps. By addressing defects preliminarily rather than performing separate repair operations later, the method integrates the repair function into the existing manufacturing flow. This timing strategy minimizes the impact on overall process complexity while achieving the reliability benefits of defect correction.

Inventive Principle:

Principle #10Preliminary action

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 reduces the resistance of electrical contacts, improves data rate, and prevents current leakage by repairing defects in the conductive material, thereby enhancing the electrical performance and reliability of semiconductor structures.

Implementation Method 1

implanting a dopant material with a concentration of at least 10^15 atom/cm3 into regions of polysilicon material within trenches to repair defects

Methodology Applied

Scientific EffectIon Implantation: Ion Implantation

Implementation Method 2

annealing to form a doped polysilicon contact, reducing resistance and preventing current leakage

Methodology Applied

Scientific EffectAnnealing: Annealing

Data Source

PatentUS11830762B2Method of manufacturing semiconductor structure

Publication Date: 2023.11.28 NAN YA TECH

AI summary

The present disclosure provides a method of manufacturing a semiconductor structure having an electrical contact. The method includes providing a semiconductor substrate; forming a dielectric structure over the semiconductor substrate, the dielectric structure having a trench; filling a polysilicon material in the trench of the dielectric structure; detecting the polysilicon material to determine a region of the polysilicon material having one or more defects formed therein; implanting the polysilicon material with a dopant material into the region; and annealing the polysilicon material to form a doped polysilicon contact.