Ion Implanter X-Ray Rocking Curve Alignment for SiC Wafers

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Solution Overview

Problem

The challenge lies in accurately aligning an ion beam with the complex crystalline structures of alternative semiconductor workpieces like silicon carbide (SiC) for effective ion implantation, as their orientations can vary significantly, leading to inconsistent process results due to the complexity of their polytypes and tilt angles.

Innovation Solution

An ion implanter system that utilizes X-ray diffraction (XRD) to perform a rocking curve test to determine the crystalline orientation of the workpiece, allowing for precise alignment of the ion beam by calculating and adjusting the X-tilt and Y-tilt angles to facilitate channeling of the ion beam into the crystalline structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If ion implantation is performed on alternative workpieces with complex crystalline structures like SiC, then semiconductor device manufacturing capability is improved, but alignment precision deteriorates due to varying crystalline orientations and polytypes

Engineering Contradiction:

Improvemanufacturing capability for alternative workpiecesVSAvoidalignment precision

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The system performs a rocking curve test before ion implantation to determine the crystalline orientation of the workpiece. This preliminary measurement allows the system to calculate the correct alignment angles (phi and theta) in advance, ensuring precise alignment during the subsequent implantation process despite the complex and varying crystalline structures of alternative workpieces like SiC

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system uses XRD measurement to obtain feedback on the workpiece's crystalline orientation, then uses this information to calculate and adjust the alignment angles. This feedback loop ensures that each workpiece is aligned precisely according to its specific crystalline structure, resolving the alignment precision issue while maintaining versatility across different workpiece types

Inventive Principle:

Principle #23Feedback

2Manufacturing precision

If rocking curve test is performed to determine crystalline orientation, then alignment precision is improved, but process time increases

Engineering Contradiction:

Improvealignment precisionVSAvoidprocess time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The system changes the measurement parameters by performing the rocking curve test at multiple predetermined locations on the workpiece surface. This approach efficiently captures the crystalline orientation information needed for alignment while minimizing the total measurement time through optimized sampling strategy

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The system performs the rocking curve test at a plurality of locations rather than attempting to measure the entire surface, which would be time-consuming. This partial measurement approach provides sufficient information for accurate alignment while significantly reducing the process time

Inventive Principle:

Principle #16Partial or excessive action

3Measurement precision

If multiple locations are tested on the workpiece, then measurement accuracy is improved, but measurement complexity increases

Engineering Contradiction:

Improveorientation measurement accuracyVSAvoidmeasurement complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The measurement process is segmented into multiple discrete steps: positioning the workpiece, measuring at the first location, moving to the second location, measuring again, and repeating as needed. This segmentation of the measurement process into manageable segments improves measurement accuracy while keeping each individual measurement step relatively simple

Inventive Principle:

Principle #1Segmentation

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 ensures accurate alignment of the ion beam with the crystalline structure, enhancing the depth of ion implantation and reducing damage to the workpiece, while improving process consistency and yield by maximizing channeling efficiency.

Implementation Method 1

an Xray source to generate an Xray beam

Methodology Applied

Scientific EffectX-ray generation: X-Ray

Implementation Method 2

at least a portion of the Xray beam impacts the workpiece to produce diffracted Xrays

Methodology Applied

Scientific EffectX-ray diffraction: Bragg Diffraction

Implementation Method 3

an ion source to generate an ion beam

Methodology Applied

Scientific EffectIon beam generation: Ion Beam

Data Source

PatentUS20240222070A1Xray diffraction angle verification in an ion implanter

Publication Date: 2024.07.04 APPLIED MATERIALS INC

AI summary

An ion implanter to facilitate channeling of an ion beam into a crystalline structure of a workpiece is disclosed. The ion implanter comprises an ion source to generate an ion beam, a platen to support the workpiece having the crystalline structure, an Xray source to generate an Xray beam, wherein at least a portion of the Xray beam impacts the workpiece to produce diffracted Xrays, an Xray detector positioned to receive the diffracted Xrays, and a controller, in communication with the Xray source, the platen, and the Xray detector. The controller contains instructions, which enable the ion implanter to perform a rocking curve test after the workpiece is disposed on the platen and calculate an orientation of the platen for an ion implant process based on a result of the rocking curve test to facilitate channeling of the ion beam into the crystalline structure of the workpiece.