Ion Implantation Angle Adjustment for Semiconductor Uniformity
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Solution Overview
Problem
Semiconductor device manufacturing processes face challenges due to device dimension deviations caused by process variations, leading to non-uniform threshold voltage and breakdown voltage across wafers, especially as device size scales down.
Innovation Solution
A method involving the formation of projections on a substrate with varying intervals, where ions are implanted at a calculated angle based on the height and interval distribution of these projections to create doped regions with different doping levels, ensuring uniform electrical characteristics across the wafer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional manufacturing processes are used, then device fabrication can be completed, but device dimension deviations occur leading to non-uniform electrical characteristics
Solution Approach 1:
The patent applies local quality by implanting ions at different angles for different interval groups. Specifically, ions are implanted at a first angle for intervals in a first range, and at a second angle for intervals in a second range. This creates locally optimized doping profiles that compensate for dimension variations in different regions, resulting in uniform electrical characteristics across the entire wafer despite process variations
Solution Approach 2:
The patent changes the ion implantation angle parameter based on the interval between projections. By calculating different implantation angles corresponding to different interval ranges and executing multiple implantation processes with varying angles, the method compensates for dimension deviations and achieves uniform threshold voltages and breakdown voltages across devices with different dimensions
2Productivity
If wafer size increases or device size is reduced, then manufacturing capacity improves, but device dimension deviations become larger
Solution Approach 1:
The patent dynamically adjusts the ion implantation angle parameter based on measured interval distributions. By calculating optimal implantation angles for different interval ranges and executing multi-angle implantation processes, the method compensates for dimension deviations that occur with larger wafers or smaller devices, maintaining manufacturing precision while enabling higher productivity
3Reliability
If multiple implantation processes with different angles are executed, then electrical characteristic uniformity improves, but process complexity increases
Solution Approach 1:
The patent performs preliminary measurement of the interval distribution before ion implantation. Based on these pre-measured intervals, the system calculates the appropriate implantation angles and doses in advance. This preliminary characterization enables the subsequent multi-angle implantation process to be executed systematically, achieving uniform electrical characteristics while managing process complexity through structured planning
Solution Approach 2:
The patent uses measured interval distribution data as feedback to determine the ion implantation parameters. The measured intervals feed into angle calculation algorithms that determine the optimal implantation angles for different interval groups. This feedback loop ensures that the implantation process is adapted to the actual wafer geometry, achieving uniform electrical characteristics despite variations in device dimensions
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 results in more uniform electrical characteristics, such as threshold voltage and breakdown voltage, even with dimension deviations, by self-aligned ion implantation, narrowing the distribution and improving the operational current region of semiconductor devices.
Implementation Method 1
implanting ions at the calculated implantation angle
Data Source
AI summary
A semiconductor device manufacturing method includes preparing a wafer having projections formed on a substrate. The projections project upward from a surface of the substrate and have a height measured from the surface of the substrate. The method further includes determining an interval distribution representing a distribution of intervals between neighboring projections and calculating an implantation angle based on the height and the interval distribution. The implantation angle is an angle between a normal direction of the substrate and an implantation direction. The method also includes implanting ions at the calculated implantation angle.