Fin-Type Semiconductor Region Impurity Doping Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional fin-FETs face challenges in achieving desired transistor characteristics due to disparities in impurity region dosages and junction depths between upper and side portions of fin-semiconductor regions, leading to uneven resistance and current localization, which prolongs the plasma doping process time.
Innovation Solution
A method involving a plasma doping process that introduces a first impurity with a higher dosage in both upper and side portions of fin-semiconductor regions, followed by introducing oxygen or nitrogen as a second impurity with a higher amount in the upper portions to equalize resistance, allowing for shorter processing times and improved transistor characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional plasma doping process is used to introduce impurities into fin-semiconductor regions, then impurity regions are formed in upper and side portions, but disparities in impurity dosage and junction depth occur between upper and side portions, leading to uneven resistance and prolonged process time
Solution Approach 1:
The patent segments the impurity introduction process into two distinct stages: first introducing a base level of impurities uniformly, then introducing additional impurities selectively to specific regions. This segmentation allows different portions of the fin-semiconductor region to receive tailored impurity dosages, achieving uniform resistance characteristics while maintaining efficient process timing.
Solution Approach 2:
The patent applies preliminary action by first introducing a first impurity to establish a baseline doping level across the fin-semiconductor region before introducing the second impurity. This preliminary impurity introduction creates a foundation that enables subsequent selective doping to achieve uniform resistance without requiring excessive process time.
2Manufacturing precision
If impurity dosage in side portions is increased to match upper portions, then resistance uniformity improves, but process time increases due to extended plasma doping requirements
Solution Approach 1:
The patent applies local quality by introducing a second impurity with different characteristics than the first impurity, specifically targeting regions where additional doping is needed. The second impurity has a different diffusion coefficient and junction depth, allowing selective enhancement of impurity concentration in specific portions of the fin-semiconductor region to achieve local resistance uniformity without globally extending process time.
Solution Approach 2:
The patent changes parameters by introducing a second impurity with different physical and chemical properties compared to the first impurity. This includes different diffusion coefficients, solubility characteristics, and junction depths. By changing these parameters, the process achieves uniform resistance characteristics more efficiently without requiring prolonged plasma doping times.
3Productivity
If single impurity introduction is used, then process is simple and fast, but resistance uniformity between upper and side portions cannot be achieved
Solution Approach 1:
The patent employs composite materials by introducing two different impurities into the fin-semiconductor region. The first impurity establishes a base doping level, while the second impurity with different diffusion and electrical characteristics provides additional doping to achieve uniform resistance. This composite approach combines the advantages of both impurities to achieve resistance uniformity while maintaining reasonable process efficiency.
Solution Approach 2:
The second impurity acts as an intermediary that mediates between the base doping level provided by the first impurity and the desired final resistance uniformity. By introducing this intermediate doping step with different characteristics, the process bridges the gap between simple single-impurity doping and the complex resistance uniformity requirement, achieving both goals simultaneously.
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 enables the formation of semiconductor devices with uniform resistance across fin-semiconductor regions, reducing process time and enhancing transistor performance by setting side portion resistance equal to or less than upper portion resistance, thus achieving desired characteristics efficiently.
Implementation Method 1
introducing a first impurity which produces a donor level or an acceptor level in a semiconductor into an upper portion and side portions of the fin-semiconductor region by a plasma doping process
Implementation Method 2
introducing oxygen or nitrogen as a second impurity into the upper portion and side portions of the fin-semiconductor region
Data Source
AI summary
A fin-semiconductor region (13) is formed on a substrate (11). A first impurity which produces a donor level or an acceptor level in a semiconductor is introduced in an upper portion and side portions of the fin-semiconductor region (13), and oxygen or nitrogen is further introduced as a second impurity in the upper portion and side portions of the fin-semiconductor region (13).