Wafer Heating and Holding Device for Stable In-Plane Temperature Distribution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wafer heating methods for semiconductor manufacturing processes, such as spin etching, suffer from inefficiency and poor precision in maintaining stable in-plane temperature distribution, leading to unstable etching and prolonged processing times due to external influences and temperature-related issues with chemical solutions.
Innovation Solution
A wafer heating and holding device with heating means positioned between the rotary table and the wafer, using a carbon or halogen heater, and a reflective board to prevent heat transmission to the table, allowing direct and efficient heating of the wafer while maintaining in-plane temperature distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If heating means is provided lateral to and above the wafer using hot air, then the wafer can be heated, but the heating efficiency and temperature precision are poor leading to unstable etching distribution
Solution Approach 1:
A transparent heating plate is introduced as an intermediary between the hot air source and the wafer. The heating plate transfers heat directly to the wafer through contact, eliminating the inefficiencies of lateral hot air heating while maintaining temperature uniformity across the wafer surface.
Solution Approach 2:
The patent replaces the mechanical convection-based hot air heating system with a direct thermal contact system using a transparent heating plate. This substitution provides superior temperature control and uniformity by eliminating the unpredictable heat transfer characteristics of convective heating.
2Productivity
If the etchant temperature is raised to speed up processing, then the processing speed increases, but the etchant concentration drops due to evaporation and processing time is prolonged
Solution Approach 1:
The system incorporates temperature sensing and control mechanisms that monitor the wafer temperature during etching. By providing precise thermal feedback control, the system maintains optimal etchant temperature without excessive heating, thereby preventing evaporation losses while ensuring high etching speed.
Solution Approach 2:
The patent changes the heating method from indirect hot air convection to direct thermal contact through a transparent heating plate. This parameter change in the heating mechanism enables precise temperature control that prevents etchant evaporation while maintaining high processing speed.
3Temperature
If external heating methods are used, then the wafer can be heated, but the wafer is subjected to external influence leading to unstable etching
Solution Approach 1:
The transparent heating plate serves as a mediator that provides thermal energy to the wafer in a controlled and uniform manner. This intermediary structure shields the wafer from direct exposure to external hot air currents and other environmental disturbances, thereby improving etching stability.
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
Enables stable and efficient heating of wafers during rotation, reducing external influences and prolonging the life of volatile etchants like HF, while maintaining consistent etching rates and reducing the risk of HF evaporation.
Implementation Method 1
an upper surface of a wafer supported by and fixed to an upper surface of a spin table is heated indirectly with the use of hot air by air hot jet means or similar heating means provided lateral to and above the wafer
Implementation Method 2
a heating means 14 provided above the rotary table 12 and below the wafer W without being in contact with the wafer W to heat the wafer W
Implementation Method 3
a reflective board 16, and disposes the heating means 14 on the reflective board 16
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
Provided are a wafer heating and holding mechanism for a rotary table, a wafer heating method for a rotary table, and a wafer rotating and holding device with which a wafer put on a rotary table can be heated while being rotated stably under a state in which an in-plane temperature distribution of the wafer is maintained. The wafer heating and holding mechanism for a rotary table of a wafer rotating and holding device comprises: a rotary shaft; a rotary table placed on an end of the rotary shaft and configured to hold a wafer on an upper surface of the rotary table; a drive motor configured to supply motive power to the rotary shaft; and heating means provided above the rotary table and below the wafer while avoiding contact with the wafer to heat the wafer.