Chamber Accumulation Compensation for Trim Process

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Solution Overview

Problem

Double patterning processes in atomic layer deposition face challenges in minimizing wafer-to-wafer variability due to material accumulation in the processing chamber, which affects etch rates and impedance, leading to non-uniform critical dimension and imbalance.

Innovation Solution

A controller system that adjusts radio frequency (RF) power and duration of the etching step based on accumulation values, using stored data to calculate adjustment factors and maintain desired etch rates, thereby compensating for changes in chamber impedance and reducing variability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If material accumulation is allowed to occur during deposition steps, then productivity is improved by maintaining continuous processing, but manufacturing precision deteriorates due to non-uniform etch rates and critical dimension variation

Engineering Contradiction:

Improvecontinuous processingVSAvoidcritical dimension uniformity

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The system implements feedback control by monitoring material accumulation in the processing chamber and dynamically adjusting RF power parameters for subsequent etching steps. The controller modifies etch power based on detected accumulation levels, ensuring consistent etch rates and critical dimensions despite continuous processing conditions.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The invention changes the RF power parameter dynamically based on material accumulation conditions. By adjusting power levels in response to accumulation, the system maintains optimal etch performance throughout continuous processing cycles without requiring chamber evacuation or cleaning interruptions.

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If RF power is increased to compensate for material accumulation, then etch rate consistency is improved, but energy consumption increases

Engineering Contradiction:

Improveetch rate consistencyVSAvoidRF power consumption

Core Design Contradiction:

Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The system employs dynamic RF power adjustment rather than static high power settings. The controller modulates power levels in real-time based on actual material accumulation conditions, applying compensation only when and where needed. This dynamic approach maintains etch consistency while minimizing unnecessary energy consumption during low-accumulation periods.

Inventive Principle:

Principle #15Dynamics

3Manufacturing precision

If the etching step duration is extended to compensate for accumulation, then critical dimension control is improved, but processing time increases

Engineering Contradiction:

Improvecritical dimension controlVSAvoidetching step duration

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The invention primarily changes RF power parameters rather than extending etch duration. By adjusting power levels to compensate for accumulation effects, the system maintains optimal etch rates without requiring longer processing times, thus preserving both precision and productivity.

Inventive Principle:

Principle #35Parameter changes

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 system effectively reduces wafer-to-wafer variability in etching by dynamically adjusting RF power and etching duration, ensuring consistent etch rates and improving processing chamber performance.

Implementation Method 1

a processing chamber configured to perform etching and deposition on a substrate

Methodology Applied

Scientific EffectPlasma: Plasma

Implementation Method 2

compensating for changes in chamber impedance

Methodology Applied

Scientific EffectImpedance: Electrical Resistance

Data Source

PatentUS10847352B2Compensating chamber and process effects to improve critical dimension variation for trim process

Publication Date: 2020.11.24 LAM RES CORP

AI summary

A controller includes memory that stores data correlating accumulation values to respective adjustment factors. The accumulation values correspond to accumulation of material on surfaces within a processing chamber and the respective adjustment factors correspond to adjustments to a control parameter of RF power provided to the processing chamber. An accumulation calculation module is configured to calculate a first accumulation value indicating an amount of accumulation of the material. An RF power control module is configured to receive the first accumulation value, receive at least one of a setpoint power and a duration of an etching step, retrieve the stored data from the memory, adjust the control parameter based on the first accumulation value, the at least one of the setpoint power and the duration of the etching step, and the stored data, and control the RF power provided to the processing chamber in accordance with the adjusted control parameter.