Application of infrared radiators in heating semiconductor silicon wafers (wafers)

Wafers, also known as semiconductor wafers or silicon wafers, are one of the fundamental materials widely used in the semiconductor industry. Wafer heating is a crucial step in the semiconductor manufacturing process, which aims to perform necessary heat treatment on the wafer during the preparation of integrated circuits and other semiconductor devices. It can remove organic matter and bubbles, activate materials, adjust shapes, enhance material structures, etc., ensuring the surface purity and quality of silicon wafers. In this process, the wafer usually needs to be uniformly heated to a specific temperature to enable it to perform better in various application fields, in order to promote or optimize subsequent process steps.

Heating is one of the crucial steps in the preparation process from silicon wafers to wafers, which involves many process steps and generally includes the following aspects:

(1) Crystal growth: In the process of crystal growth, silicon material needs to be melted and heated to a certain temperature. By controlling the temperature and time, the silicon material crystallizes and gradually grows into crystals.

(2) Cutting silicon wafers: In the grown crystals, they need to be divided into thin sheets by cutting. During the cutting process, the silicon wafers need to be heated to ensure cutting quality and integrity.

(3) Semiconductor processing: After cutting silicon wafers into wafers, semiconductor processing is required, including multiple process steps such as cleaning, deposition, photolithography, etching, ion implantation, etc. Different process steps require different heating temperatures and times to complete their respective functions.

(4) Annealing: In semiconductor processing, in order to eliminate lattice defects and improve crystal quality, annealing treatment is required, which involves heating the wafer to a certain temperature and maintaining it for a certain period of time to eliminate defects in the crystal.

If the heating of the silicon wafer is uneven, it may cause a series of problems:

（1）Lattice deformation: Uneven heating of silicon wafers can cause different stresses on the lattice in different regions, which may lead to lattice deformation or disorder. Lattice deformation can affect the crystal structure of silicon wafers, potentially causing changes in their electrical properties and ultimately leading to silicon wafer failure.

（2）Structural changes: Silicon wafers expand and contract at different temperatures. If the heating of the silicon wafers is uneven, it will lead to uneven thickness and shape of the silicon wafer surface, which does not meet the design requirements. In addition, thermal stress may cause defects such as cracks or burrs on the surface of silicon wafers.

（3）Product quality degradation: If the silicon wafer is heated unevenly, it will result in the manufactured silicon wafer having irregular shapes, sizes, and thicknesses, which will reduce the product quality of the silicon wafer. During the production process, silicon wafers with uneven heating need to be discarded, which will lead to an increase in costs.

（4）Increased failure rate: Thermal non-uniformity can cause silicon wafers to be subjected to high temperature heat in certain areas, accelerating the aging and failure of components in the wafer, and even leading to a decrease in overall performance of the wafer to a certain extent that it cannot continue to be used.

How to avoid uneven heating of silicon wafers?

During the heating process of the wafer, it is required that the temperature distribution on the wafer surface be as uniform as possible to ensure consistent device performance across the entire wafer. Uneven temperature distribution may lead to differences in device performance and affect product quality. Using an infrared radiator for heating, the light is focused on the wafer and quickly heated to the desired temperature. This stage may only take a few seconds to several tens of seconds. Quickly respond and adjust the heating power to reduce temperature overshoot or insufficiency, effectively preventing temperature fluctuations that may cause process problems, allowing the heated surface to receive the average red line radiation energy, effectively reducing the adverse process quality problems caused by uneven temperature.

Compared to traditional heating methods, infrared radiators have the following significant advantages in heating:

(1) High control accuracy: Precise temperature control greatly improves the quality of wafer production;

(2) Good thermal uniformity: uniform heating temperature distribution, precise temperature control, and fast response;

(3) Energy saving and environmental protection: The heat generated by the infrared heater during the heating process is mainly concentrated on the surface of the object, so there is no need to heat the entire air, reducing energy waste and not producing exhaust gas and other pollutants. It is a more environmentally friendly heating method.

Infrared heating is a fast, accurate, and environmentally friendly wafer heating method with broad application prospects. The application of this technology can improve the production speed and quality of wafers, enhance the manufacturing performance and stability of semiconductor equipment, and promote the continuous improvement of semiconductor production and international market competitiveness. With the continuous development and improvement of infrared heating technology, it is widely used in industries such as battery manufacturing, semiconductor manufacturing, electronic component manufacturing, and ceramic processing.