Counter-Based Time Compensation in Reactive Magnetron Sputtering
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Solution Overview
Problem
Reactive magnetron sputtering processes face challenges in defect control, particularly in maintaining consistent film properties and thickness across multiple substrate runs due to shifting process parameters caused by periodic pure titanium sputtering in titanium nitride (TiN) deposition.
Innovation Solution
A method involving sputtering a metal target using a first plasma formed from an inert gas, followed by sputtering a metal compound using a second plasma with a reactive gas, and adjusting deposition time based on calculated counters to maintain consistent film properties and thickness across substrates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If periodic pure titanium sputtering is implemented to mitigate brittleness and target surface formation, then film quality is improved, but process parameter stability deteriorates due to significant alteration of target and process kit surfaces
Solution Approach 1:
The patent applies preliminary action by performing a conditioning sputter step before the main deposition process. This preliminary step modifies the target and process kit surfaces in a controlled manner, preparing them for subsequent depositions and preventing unwanted reactions during the main process, thereby maintaining process parameter stability while achieving film quality improvement.
Solution Approach 2:
The patent implements continuity of useful action by integrating the conditioning sputter step into a continuous multi-step deposition sequence. Rather than performing periodic pure titanium sputtering that disrupts the process, the conditioning step is seamlessly incorporated into the deposition workflow, maintaining continuous useful action while achieving both film quality and process stability.
2Strength
If periodic pure titanium sputtering is performed to mitigate brittleness of TiN films, then film brittleness is reduced, but deposition time increases due to additional process steps
Solution Approach 1:
The patent merges the conditioning function with the deposition process by combining multiple objectives into a unified multi-step sequence. The conditioning sputter step is integrated with the deposition parameters and timing, allowing the process to achieve both film quality improvement and productivity maintenance through coordinated parameter optimization across steps.
Solution Approach 2:
The patent applies parameter changes by optimizing sputtering parameters (power, gas flow rates, pressure) for each step of the deposition sequence. By carefully controlling parameter transitions between conditioning and deposition phases, the process achieves film quality improvement while minimizing additional deposition time through efficient parameter management.
3Manufacturing precision
If deposition time is adjusted to compensate for process shifting, then film thickness consistency is improved, but process complexity increases due to counter calculations and dynamic adjustments
Solution Approach 1:
The patent implements feedback by using real-time monitoring of process parameters (gas flow rates, power, pressure) to dynamically adjust deposition time. The system calculates counters based on actual process conditions and modifies deposition parameters accordingly, achieving film thickness consistency through closed-loop feedback control rather than fixed predetermined times.
Solution Approach 2:
The patent applies dynamics by transitioning from static, fixed deposition times to dynamic, adaptive deposition time adjustment. The system continuously monitors process conditions and modifies deposition parameters in real-time based on calculated counters, making the process responsive to actual conditions while maintaining manufacturing precision through controlled dynamic adjustments.
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 method significantly reduces drifting variations in film thickness, sheet resistivity, and resistivity across multiple substrate runs, ensuring consistent deposition of metal compound layers like titanium nitride (TiN).
Implementation Method 1
sputtering target material from a metal target for a first amount of time using a first plasma formed from an inert gas
Implementation Method 2
reactive magnetron sputtering is the sputtering of an elemental target containing one or more elements in the presence of a gas that will react with the target materials to form a compound inside the reactor
Implementation Method 3
using a first plasma formed from an inert gas and a first amount of power applied to the metal target
Data Source
AI summary
A method of processing a substrate includes: sputtering target material for a first amount of time using a first plasma formed from an inert gas and a first amount of power; determining a first counter, based on a product of a flow rate of the inert gas, the first amount of power, and the first amount of time; sputtering a metal compound material for a second amount of time using a second plasma formed from a process gas comprising a reactive gas and an inert gas and a second amount of power; determining a second counter based on a product of a flow rate of the process gas, the second amount of power, and the second amount of time; determining a third counter; and depositing a metal compound layer onto a predetermined number of substrates, wherein a deposition time for each substrate is adjusted based on the third counter.