Lots of electronic devices have increased their integration degrees for improving their own performance and miniaturization.
For further performance enhancement on these electronic devices, thermal analysis based on experimental and analytical approach, and thermal design dealing with structural modification resulting in physical response, are essential processes based on heat transfer technology. We have conducted a variety of project with major manufacturing companies for modern electronic devices. In particular, we evaluated thermal performance for LED display systems considering conjugated heat transfer for enhancing thermal reliability and life time.
In the semiconductor process, the main focus is to enhance yield rate during whole processes. A wafer process is based on the semiconductor processes. CVD(Chemical Vapor Deposition) and PVD(Physical Vapor Deposition) is represented in wafer processes. Especially, CVD to conduct wafer patterning is widely used since CVD is able to perform several wafers deposition at the same time.
The major issues in CVD are quality and epitaxial growth of crystal which are related to the temperature uniformity of wafer. To achieve these concerns, thermal characteristics of CVD should be investigated on experiment and simulation. We have already performed a lot of projects to study on thermal characteristics of CVD processes. Also, we can estimate conduction, convection and radiation using numerical simulation during CVD processes.
The phase-change memory device, which is regarded as one of the most promising candidate for next-generation non-volatile memory device, is operated by means of electrical (Joule) heat that enables a reversible transition between two distinct phases, namely amorphous and (poly)crystalline. The major current issues for phase-change memory are the low write speed, high energy consumption, and low endurance.
To enhance the write speed and reduce the energy consumption, overall thermal resistance of the device should be as high as possible in order to capture the joule heat and minimize the heat loss. Using co-doping technique during the deposition of phase-change material, growth of crystalline grains can be significantly suppressed, leading to reduced electrical and thermal conductivity. Also, enhancing the write speed and energy efficiency can be achieved by appropriate design in a way that the reset current and the associated joule heat are more concentrated.
A nanoscale trench structure is a representative of such strategy. By forming a nanotrench structured phase-change layer, current can be effectively confined that enables more localized joule heating and heat capturing. This results in reduction of reset current as well as energy consumption.
Moreover, it is evident that the phase-change memory will suffer from severe thermal damages and failures because of various extreme features such as instantaneous temperature change in order of 1012 K/s, excess temperature change across interfaces due to thermal boundary resistances, and volume change during phase transition. Therefore, thermal stress should also be addressed in order to secure the operation reliability.
Heat transfer is essential factor for bio-system applications. Precise control of local temperature maintaining temperature graduation for a certain
spatial region is required for designing practical bio-application devices including PCRs (Polymerase Chain Reaction Devices),
which are fundamental equipments for the multiplication of DNAs. Based on the thermal design processes for sufficient reliability and endurance,
we have tried to enhance the performance of the devices for fast response time and portable applications by simplifying thermal management system.