Ion Beam Angle Measurement via Shadowing Structures
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Solution Overview
Problem
Current methods for measuring ion beam angle in semiconductor fabrication are not sensitive enough, particularly for low-energy implants, and are either expensive or time-consuming, lacking a method to detect angle errors in low-energy source/drain extension implants without fabricating transistors.
Innovation Solution
The method involves forming shadowing structures on a substrate perpendicular to the ion beam path, which interrupts the beam to create implanted and non-implanted areas, allowing for the measurement of ion beam angle by determining the implanted surface area and calculating the angle based on the non-implanted surface area, applicable across various energies and species.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If crystal channeling or transistor-based methods are used to measure ion beam angle, then measurement capability is provided, but sensitivity for low energy implants is insufficient or the process becomes expensive and time consuming
Solution Approach 1:
The patent uses shadowing structures that create a geometric shadow pattern on the substrate, which is a simplified copy of the beam angle information. Instead of measuring the beam angle directly through complex transistor fabrication or crystal channeling, the system projects the angular information onto a 2D shadow pattern that can be measured quickly and sensitively, resolving the contradiction between measurement precision and time loss
Solution Approach 2:
The patent replaces the mechanical/transistor-based measurement systems with a geometric shadowing approach. By using simple shadowing structures and measuring the shadow pattern geometry, the system achieves high sensitivity for low energy implants without the complexity and time requirements of transistor fabrication or crystal channeling methods
2Measurement precision
If traditional measurement methods are used, then angle detection is possible, but the process is expensive and requires transistor fabrication
Solution Approach 1:
The shadowing structures create a geometric shadow pattern that copies the beam angle information in a simplified form. This allows angle detection without requiring expensive transistor fabrication or complex crystal channeling setups, achieving the same measurement capability through a much simpler manufacturing process
Solution Approach 2:
The shadowing structures are simple, temporary features formed on the substrate that serve their measurement purpose and can be removed or ignored. They replace expensive, complex transistor-based measurement systems with simple geometric features that are cheap to create and eliminate the need for costly transistor fabrication and weeks-long measurement 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 approach provides a sensitive and cost-effective method to detect ion beam angle errors, applicable to low-energy implants, enhancing transistor performance and product yield by accurately measuring angle variations without the need for transistor fabrication.
Implementation Method 1
a plurality of shadowing structures extending substantially perpendicular from an upper surface of the substrate, directing an ion beam toward the substrate, the plurality of shadowing structures interrupting an incident angle of the ion beam
Data Source
AI summary
A device and method for measuring ion beam angle with respect to a substrate is disclosed. The method includes forming a plurality of shadowing structures extending substantially perpendicular from an upper surface of the substrate, directing an ion beam toward the substrate, the plurality of shadowing structures interrupting an incident angle of the ion beam to define implanted and non-implanted portions of the substrate. The method further includes measuring the dose of implanted species within the substrate, determining an implanted surface area as a function of measuring the dose of implant, determining non-implanted surface area based on the implanted surface area, and obtaining the ion beam angle as a function of the non-implanted surface area.