Ion Implantation Tilt Correction Using Ejected Ion Distribution
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Solution Overview
Problem
Ion implantation processes in semiconductor fabrication face challenges in maintaining precise control over the tilt angle of ion implantation, leading to deviations from theoretical doping profiles and increased channeling effects, which result in substrate damage and reduced yield.
Innovation Solution
An ion implantation apparatus and method that utilize an ion-collecting device to record the distribution and number of ejected ions, with a control unit calculating tilt angle deviations and adjusting the tilt angle to minimize ejected and channeling ions, thereby optimizing the implantation process and improving doping accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the tilt angle of ion implantation is not precisely controlled, then the implantation process is simpler to operate, but the doping profile deviates from theoretical values and channeling effects increase
Solution Approach 1:
The patent employs a feedback mechanism where the distribution of ejected ions is detected and used to determine a correction angle, which then adjusts the tilt angle of the ion implantation. This closed-loop control system continuously monitors the implantation process and makes real-time adjustments to maintain precise doping profiles while minimizing channeling effects.
Solution Approach 2:
The patent replaces direct mechanical tilt angle control with an indirect control method using ejected ion distribution as a sensor. Instead of mechanically adjusting the tilt angle based on theoretical calculations, the system uses the physical phenomenon of ion ejection patterns to feedback-controlled adjustment, substituting mechanical precision requirements with detection and calculation processes.
2Productivity
If the tilt angle deviates from the theoretical value, then the ion implantation process is faster, but substrate damage increases due to channeling effects
Solution Approach 1:
The system uses feedback control where the distribution of ejected ions during ion implantation is detected and analyzed to determine a correction angle. This correction angle is then applied to adjust the tilt angle in real-time, preventing excessive channeling effects and substrate damage while maintaining high implantation speeds throughout the process.
Solution Approach 2:
The patent performs preliminary detection of the ion distribution pattern before completing the full implantation process. By analyzing the ejected ion distribution early in the process, the system determines the necessary tilt angle correction in advance, allowing subsequent implantation to proceed at optimal angles without causing substrate damage.
3Measurement precision
If an ion-collecting device and control system are added to monitor and adjust tilt angle, then doping accuracy improves, but device complexity increases
Solution Approach 1:
The ion-collecting device serves multiple functions: it collects ejected ions for analysis, provides data for determining correction angles, and enables real-time monitoring of the implantation process. This multi-functional approach consolidates measurement and control capabilities into a single integrated system, reducing overall device complexity despite the added precision capabilities.
Solution Approach 2:
The system introduces an intermediary calculation process that converts the complex task of direct tilt angle measurement into a simpler measurement of ejected ion distribution. The correction angle is calculated as an intermediary value that mediates between the detected ion pattern and the required tilt angle adjustment, simplifying the control architecture while maintaining high measurement precision.
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 enhances the precision and quality of ion implantation by reducing the number of ejected and channeling ions, minimizing substrate damage, and ensuring a desired doping profile, even under varying implantation conditions.
Implementation Method 1
an ion-collecting device to collect a distribution and a number of ejected ions from the ion beam scan over the target
Implementation Method 2
In an IMP process, ions are accelerated to bombard a solid target (e.g., substrate or film), thereby changing the properties (e.g., physical, chemical, and/or electrical properties) of the target
Data Source
AI summary
The present disclosure describes a system and a method for an ion implantation (IMP) process. The system includes an ion implanter configured to scan an ion beam over a target for a range of angles, a tilting mechanism configured to support and tilt the target, an ion-collecting device configured to collect a distribution and a number of ejected ions from the ion beam scan over the target, and a control unit configured to adjust a tilt angle based on a correction angle determined based on the distribution and number of ejected ions.