Pattern-Selective Heating for Semiconductor Etch Uniformity
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Solution Overview
Problem
Existing semiconductor manufacturing techniques lack the ability to achieve localized heating with sufficient spatial resolution within the die structures, leading to non-selective etch rate variations across the wafer, which complicates material removal and deposition processes.
Innovation Solution
A pattern-selective heating technique that utilizes electromagnetic radiation with specific absorption properties to create a temperature field across the processing area, allowing for selective material removal or deposition based on pattern density, enabling localized heating of target patterns within the die.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional multizone heating chuck is used for wafer-level temperature control, then large scale wafer variability is addressed, but spatial resolution is insufficient for structure-level selective heating
Solution Approach 1:
The patent applies local quality by making different regions of the wafer surface have different thermal properties through selective deposition of absorbing material. Regions with higher pattern density receive more absorbing material, creating localized heat generation zones that correspond to specific structure types, thereby achieving structure-level selective heating with sufficient spatial resolution
Solution Approach 2:
The patent introduces an intermediary absorbing material layer deposited on the wafer surface that mediates between the conventional heating chuck and the target structures. This absorbing material converts electromagnetic radiation into localized heat, enabling precise thermal control at the structure level while using wafer-level heating equipment
2Ease of operation
If uniform heating is applied across the wafer, then simple temperature control is achieved, but etch rate uniformity across different pattern densities deteriorates
Solution Approach 1:
The patent modifies the uniform heating approach by creating non-uniform absorbing material distribution that corresponds to pattern density variations. This allows the simple uniform electromagnetic radiation source to produce differentiated local heating effects, maintaining ease of operation while achieving etch rate uniformity across different pattern densities
Solution Approach 2:
The patent changes the thermal absorption parameter across the wafer surface by varying the amount of absorbing material deposited in different regions. Regions with higher pattern density have higher absorbing material concentration, leading to higher local heat generation and adjusted etch rates, thereby achieving uniform processing across diverse pattern densities
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 enhances the precision of material removal and deposition processes by allowing for differential etch rates across regions of varying pattern densities, improving process control and reducing non-uniformities in semiconductor devices.
Implementation Method 1
heating radiation source configured and operable to generate a temperature field profile across a processing area of the structure by application of electromagnetic radiation
Implementation Method 2
different locations of the processing area are subjected to different temperatures... creates different material removal rates by the etching material composition (different etch rates)
Data Source
AI summary
A system and method are presented for controlling a process applied to a structure comprising at least one of material removal and material deposition processes. The system comprises: a heating radiation source configured and operable to generate a temperature field profile across a processing area of the structure; and a control unit configured and operable to control operation of said heating radiation source in accordance with a predetermined pattern map within the processing area, so as to create a corresponding pattern selective profile of said temperature field across said processing area providing desired pattern selective distribution of at least one parameter characterizing the process applied to the processing area of the structure.