Gas Phase Etch Selectivity for Silicon Oxynitride and ARC
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Solution Overview
Problem
Current semiconductor manufacturing techniques face challenges in achieving selective, clean, and targeted removal of materials used in advanced patterning schemes due to poor etch selectivity and pattern damage associated with wet etch processes and dry plasma processes.
Innovation Solution
A dry non-plasma treatment system and method that involves exposing a microelectronic workpiece to a chemical environment at controlled temperatures to selectively remove target layers, using a gas-phase process that chemically alters the surface region of the target layer, allowing for precise removal without plasma generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If wet etch chemistry is applied to remove target layers, then material removal is achieved, but etch selectivity is poor and pattern damage occurs
Solution Approach 1:
The patent replaces wet chemical etching with a thermal field-based removal process. A heated susceptor selectively heats the target layer (SiOxNy or SiARC) to its decomposition temperature, causing the material to decompose and remove thermally rather than chemically. This substitution eliminates the need for wet chemistry while achieving selective removal without pattern damage.
Solution Approach 2:
The patent changes the removal mechanism from chemical reaction to thermal decomposition by controlling temperature parameters. The susceptor is heated to specific temperature ranges (e.g., 450-550°C for SiOxNy, 550-650°C for SiARC) to selectively decompose target layers while leaving other materials intact, achieving high etch selectivity through parameter control rather than chemical selectivity.
2Manufacturing precision
If dry plasma etching is used to remove target layers, then clean removal is achieved, but pattern damage is induced
Solution Approach 1:
The patent replaces plasma-based physical/chemical etching with pure thermal field-based decomposition. The heated susceptor transfers thermal energy to the target layer, causing selective thermal decomposition and removal. This eliminates plasma-induced pattern damage while maintaining clean removal capability through controlled thermal processes.
3Productivity
If conventional etching methods are used, then material removal is achieved, but selectivity between different materials is poor
Solution Approach 1:
The patent introduces spatial and material-specific quality control through the susceptor design. The susceptor makes selective thermal contact only with the target layer (SiOxNy or SiARC), heating them to decomposition temperatures while leaving other materials (silicon, silicon oxide, silicon nitride, organic dielectric layers) unaffected. This local thermal coupling achieves high material selectivity based on thermal conductivity and decomposition temperature differences.
Solution Approach 2:
The patent achieves material selectivity by controlling temperature parameters within specific ranges. Different target layers have different decomposition temperatures (SiOxNy: 450-550°C, SiARC: 550-650°C), and the susceptor temperature is precisely controlled to match the desired target layer's decomposition point, enabling selective removal based on thermal parameter optimization.
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 enables clean, selective, and targeted removal of various materials, including silicon-containing layers, with high etch selectivity and minimal pattern damage, suitable for sub-30 nm technology nodes, improving the efficiency and accuracy of pattern transfer in semiconductor manufacturing.
Implementation Method 1
exposing the surface of the workpiece to a chemical environment at a first setpoint temperature in the range of 35 degrees C. to 100 degrees C. to chemically alter a surface region of the target layer
Implementation Method 2
elevating the temperature of the workpiece to a second setpoint temperature at or above 100 degrees C. to remove the chemically treated surface region of the target layer
Implementation Method 3
exposing the surface of the workpiece to a chemical environment at a first setpoint temperature to chemically alter a surface region of the target layer
Data Source
AI summary
A method for the dry removal of a material on a microelectronic workpiece is described. The method includes receiving a workpiece having a surface exposing a target layer composed of silicon and either (1) organic material or (2) both oxygen and nitrogen, and selectively removing at least a portion of the target layer from the workpiece. The selective removal includes exposing the surface of the workpiece to a chemical environment containing N, H, and F at a first setpoint temperature to chemically alter a surface region of the target layer, and then, elevating the temperature of the workpiece to a second setpoint temperature to remove the chemically treated surface region of the target layer.