Semiconductor Channel Doping for Leakage Reduction
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Solution Overview
Problem
In high integration integrated circuits, isolation structures around semiconductor device corners accumulate charges, leading to reduced threshold voltage and increased sub-threshold leakage current, causing the kink effect and double-hump, which degrade electrical performance and yield.
Innovation Solution
A doping method is implemented involving a substrate with a channel region divided into edge and center regions, where a first conductive type dopant is used in a well implantation process for the edge regions and a second conductive type dopant is used in a separate ion implantation process for the center region, with specific width ratios and tilt angle options to prevent charge accumulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If isolation structures are formed around the top corners of the channel region, then device isolation is improved, but charges accumulate in the divots forming around the isolation structures, reducing threshold voltage and inducing sub-threshold leakage current
Solution Approach 1:
The patent applies different doping concentrations and types to different regions of the channel. Specifically, higher doping concentrations are applied to edge regions (within 10-50nm of isolation structures) while lower doping concentrations are applied to center regions, creating local quality variations that prevent charge accumulation at critical locations while maintaining overall device isolation
Solution Approach 2:
The channel region is segmented into multiple zones: edge regions adjacent to isolation structures and center regions between them. Each segment receives tailored doping treatment, allowing the patent to address the charge accumulation problem locally without compromising the isolation function globally
2Ease of manufacture
If uniform doping is applied across the entire channel region, then manufacturing process is simplified, but threshold voltage becomes non-uniform due to charge accumulation at edge regions
Solution Approach 1:
The patent implements spatially varying doping concentrations where edge regions receive different doping levels than center regions. This local quality differentiation ensures uniform threshold voltage across the channel by compensating for charge accumulation effects at isolation structure divots, while maintaining reasonable manufacturing complexity through standardized doping processes
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 method effectively prevents the kink effect and double-hump, enhancing the electrical performance and yield of semiconductor devices by ensuring uniform threshold voltages across the channel regions.
Implementation Method 1
An ion implantation process is performed on the active region exposed by the first patterned photoresist layer
Data Source
AI summary
A doping method for a semiconductor device including the following steps is provided. A substrate is provided. The substrate has a channel region. The channel region includes a first edge region, a second edge region and a center region in a channel width direction substantially perpendicular to a channel length direction, and the center region is located between the first edge region and the second edge region. A first doping process is performed on the first edge region, the second edge region and the center region by using a first conductive type dopant. A second doping process is performed on the center region by using a second conductive type dopant.