Epoxy EP112 Used in Microelectronics Fabrication

This sponsored article is brought to you by Master Bond.

Master Bond EP112 is an ultra-low-viscosity, electrically insulating, two-component heat curable epoxy system designed for demanding applications requiring optical clarity and resistance to chemicals commonly used in silicon processing. This article introduces a two-part case study involving a microelectronics fabrication, showcasing EP112’s role in bonding a silicon wafer to a glass substrate.

Part 1: The START Process and EP112’s Role

In the first part of this case study, researchers at Lawrence Livermore National Laboratory (LLNL) developed an innovative Silicon-on-Insulator (SOI) process called START (Silicon Transfer to Arbitrary Substrate). This method enables the transformation of standard bulk silicon wafers with completed circuits into SOI-like configurations without significantly increasing manufacturing costs. By using conventional fabrication techniques, the START process combines the benefits of bulk silicon electronics with those of SOI technology while maintaining cost efficiency.

A critical step in this process involved bonding a silicon wafer to a glass support substrate. EP112 was selected as the adhesive of choice due to its ultra-low viscosity, strong bonding capabilities, and high chemical resistance. The bonded structure ultimately contributed to the successful development of a prototype liquid crystal display (LCD), demonstrating EP112’s effectiveness in microelectronics fabrication.

Part 2: CMOS Wafer Thinning for SEU Resistance

In the second part of this study, LLNL researchers applied EP112 in a novel wafer-thinning process to enhance the reliability of CMOS-based integrated circuits (ICs). The objective was to reduce susceptibility to Single Event Upsets (SEUs) by significantly decreasing the charge collection volume within the silicon substrate.

To achieve this, EP112 was used to bond two substrates together, ensuring a secure attachment throughout the wafer-thinning steps. The process involved a high-temperature alkaline etching step, where EP112’s superior chemical resistance played a crucial role in preventing de-bonding. By maintaining structural integrity under these harsh conditions, EP112 enabled the successful completion of the thinning process, further demonstrating its suitability for advanced semiconductor applications.

To read more about the key parameters and requirements, and learn about the results, please download the full case study here.