Ion Implantation Apparatus Dynamic Wafer Rotation Control
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Solution Overview
Problem
Current ion implantation methods struggle to achieve uniform ion implantation across semiconductor wafers, particularly with the miniaturization of semiconductor chips, leading to non-uniformity and limitations in creating large-scale two-dimensional ion implantation distributions with a ratio of maximum to minimum ion implantation amounts exceeding five times, which restricts the ability to handle dose amount non-uniformity and two-dimensional shape patterns effectively.
Innovation Solution
The method involves scanning an ion beam in one direction and mechanically scanning the wafer perpendicular to the beam direction, varying the wafer rotation angle and scanning region length, and adjusting the beam scanning speed at each set angle to achieve a large-scale two-dimensional ion implantation distribution, allowing independent control of dose amount non-uniformity and two-dimensional shape patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a uniform ion implantation amount is formed across the entire wafer surface, then the ion implantation uniformity is improved, but the ability to handle dose amount non-uniformity and two-dimensional shape patterns in other semiconductor manufacturing processes deteriorates
Solution Approach 1:
The patent applies dynamics by making the wafer rotation angle variable rather than fixed. The rotation angle is dynamically adjusted during the ion implantation process to create intentional non-uniform two-dimensional ion implantation amount distributions. This allows the system to adapt between uniform implantation (when rotation angle is constant) and non-uniform implantation patterns (when rotation angle varies), resolving the contradiction between implantation uniformity and adaptability to handle dose amount non-uniformity.
2Ease of operation
If only scanning speed by ion beam and mechanical scanning speed by wafer are controlled, then the ease of operation is improved, but the control range of scanning speed is restricted and large-scale two-dimensional ion implantation distributions cannot be realized
Solution Approach 1:
The patent applies parameter changes by introducing the wafer rotation angle as an additional controllable parameter. Instead of only controlling scanning speeds (one-dimensional control), the system now controls scanning speed plus rotation angle (two-dimensional control). This expansion of controllable parameters enables large-scale two-dimensional ion implantation distributions with ratios of maximum to minimum implantation amounts of five times or more, while maintaining ease of operation through systematic control methods.
3Adaptability or versatility
If the ratio of maximum to minimum ion implantation amounts in the wafer surface is increased to five times or more, then the ability to handle dose amount non-uniformity is improved, but the manufacturing precision of uniform ion implantation deteriorates
Solution Approach 1:
The patent applies local quality by creating intentional non-uniform two-dimensional ion implantation amount distributions where different regions of the wafer receive different implantation amounts. By controlling the wafer rotation angle and scanning speed, the system can create specific non-uniform patterns (such as higher implantation at center or edge regions) that match the requirements of other semiconductor manufacturing processes. This resolves the contradiction by allowing uniform implantation when needed and controlled non-uniform implantation when required, with the uniformity of the non-uniform pattern itself being precisely controlled.
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 creation of a large-scale two-dimensional ion implantation distribution with a ratio of maximum to minimum ion implantation amounts of five times or more, effectively addressing non-uniformity and enabling independent control of dose amount and shape pattern uniformity, thus improving semiconductor chip performance across the wafer surface.
Implementation Method 1
An apparatus used in this process is called an ion implantation apparatus. The ion implantation apparatus has a function of generating ions using an ion source, and then forming an accelerated ion beam
Data Source
AI summary
An ion implantation method in which an ion beam is scanned in a beam scanning direction and a wafer is mechanically scanned in a direction perpendicular to the beam scanning direction, includes setting a wafer rotation angle with respect to the ion beam so as to be varied, wherein a set angle of the wafer rotation angle is changed in a stepwise manner so as to implant ions into the wafer at each set angle, and wherein a wafer scanning region length is set to be varied, and, at the same time, a beam scanning speed of the ion beam is changed, in ion implantation at each set angle in a plurality of ion implantation operations during one rotation of the wafer, such that the ions are implanted into the wafer and dose amount non-uniformity in a wafer surface in other semiconductor manufacturing processes is corrected.