A joint research team from Ulsan National Institute of Science and Technology (UNIST) and Pohang University of Science and Technology (POSTECH), led by Professor Byungjo Kim and Professor Jihwan An, has successfully developed a novel post-doping plasma (PDP) process that significantly improves the performance of DRAM, a key semiconductor memory device. As electronic devices become increasingly miniaturized, traditional manufacturing techniques struggle with issues such as leakage current and reduced stability in memory semiconductors like DRAM.

The capacitor in DRAM is a critical component for charge storage, and its performance largely depends on the quality of the dielectric layer. Aluminum-doped titanium dioxide (ATO) is an ideal dielectric material due to its high dielectric constant and excellent leakage current suppression. However, ATO prepared by conventional atomic layer deposition (ALD) suffers from lattice disorder and oxygen vacancies, leading to material instability and increased leakage current. To address this challenge, the research team introduced the PDP process, which involves depositing a TiO₂ dielectric layer via ALD, coating it with an ultra-thin aluminum oxide layer, and then treating it with a plasma composed of argon and oxygen. The plasma treatment not only promotes atomic-level migration of aluminum dopants and lattice reordering but also effectively fills oxygen vacancies, dramatically enhancing DRAM capacitor performance. Experimental data show that DRAM capacitors processed with PDP exhibit a ~30% increase in dielectric constant and a nearly 40-fold reduction in leakage current.

Professor An stated that this atomic-layer process has broad application prospects, not only for DRAM but also for next-generation electronic devices and energy storage systems. Professor Kim emphasized that understanding the fundamental interactions between plasma and materials at the atomic scale represents a major scientific breakthrough in semiconductor manufacturing, which will help Korea maintain its competitive edge in the global semiconductor industry.