Friday, March 22, 2024
Surfs are going to be up at the PRiME Symposium G01 on ALD & ALE Applications 20, in Honolulu | Oct. 6-12, 2024
Tuesday, March 19, 2024
Laser Slicing Technique Revolutionizes GaN Substrate Recycling, Paving the Way for Cost-Effective Vertical Power MOSFETs
A study led by Takashi Ishida and colleagues explored a recycling process for gallium nitride (GaN) substrates using a laser slicing technique, aiming to reduce the cost of GaN vertical power MOSFETs. GaN is noted for its potential in high-power applications due to its superior electrical properties compared to silicon. The cost of GaN devices, while expected to be lower than silicon carbide (SiC) devices, is significantly impacted by the expensive GaN substrates. The proposed recycling process involves the use of laser slicing to separate used GaN substrates into thin device chips and a remaining substrate portion, which can then be smoothed, polished, and reused for further device fabrication.
The research demonstrated that the electrical properties of devices fabricated on recycled GaN substrates, specifically lateral MOSFETs and vertical PN diodes, showed no degradation compared to those on new substrates. This indicates that the recycling process does not adversely affect the substrate's quality or the performance of subsequent devices. The study's findings suggest that this recycling method could be a viable strategy to lower the production costs of GaN-based power devices, potentially facilitating their broader adoption in high-power applications.
Tokyo Electron ALD of AlN Thin Films Report Unprecedented Uniformity on Large Batch 200 mm Tool
In the rapidly evolving world of semiconductor technology, achieving high uniformity in thin films is important for enhancing production yield and device performance. In a study led by Partha Mukhopadhyay and his team at Tokzo Electron has made significant strides in this domain, using ALD of aluminum nitride (AlN) thin films on a 200 mm large batch furnace platform. AlN is particularly relevant for gallium nitride (GaN)-based power industry, where AlN's wide bandgap, high dielectric constant, and superior thermal conductivity make it an ideal choice for various applications, including UV LEDs, transistors, and micro-electromechanical systems.
The study's focus lies in its ability to maintain extraordinary uniformity across large batches of 200 mm wafers, achieving a thickness variation of less than 0.5 Å. This level of uniformity was obtained by optimizing the ALD process in a reactor capable of handling over 100 wafers, marking a significant achievement in high-volume production environments. The research examined the effects of deposition temperatures, film thicknesses, and different substrate types, including Si, quartz, and GaN/Si(111), on the material and optical properties of the AlN films.
One of the key findings was the identification of an optimal narrow temperature window between 300°C and 350°C for the deposition process, with 350°C being the sweet spot. The study also delved into the nuanced challenges of nucleation on different substrates, revealing that substrate-inhibited growth and a non-linear deposition rate are pivotal factors to consider. This understanding is crucial for maintaining uniformity in extremely thin films, which are sensitive to the underlying substrate's crystal orientation.
From a compositional standpoint, the development showcased the high purity of the AlN films, with negligible carbon and oxygen contamination. This purity is essential for the semiconductor industry, particularly for applications where chemical stability is critical. The study's rigorous material analysis, which included techniques like XPS and TEM, provided in-depth insights into the AlN films' structural and compositional integrity.
Optically, the AlN films demonstrated a bandgap of 5.8 eV, a key attribute for their use in optoelectronic applications. The research also highlighted the refractive index's dependence on film thickness and deposition temperature, offering valuable data for the design and optimization of optical devices.
In summary, this study represents a significant progress in ALD of AlN thin films, combining high throughput with exceptional film uniformity and quality.
Thursday, March 7, 2024
Aalto University in Finland Wins Major Grant for Eco-Friendly Semiconductor Technology
Aalto University, in close collaboration with key industry players including Applied Materials in Finland (Picosun), PiBond, and Volatec, has been awarded a significant grant by Business Finland for their groundbreaking project titled “New chemistries for resource-efficient semiconductor manufacturing”. This initiative is a part of the larger "Chip Zero" Ecosystem, spearheaded by Picosun, aiming to revolutionize the semiconductor industry by developing chips that boast zero lifetime emissions—a first in Finland's tech landscape.
Led by Professors Maarit Karppinen and Antti Karttunen from Aalto's Department of Chemistry and Materials Science, the project seeks to address the pressing environmental concerns associated with semiconductor manufacturing. With the industry's carbon footprint and resource consumption at an all-time high, this co-innovation venture promises to pave the way for more sustainable production methods.
Dr. Ramin Ghiyasi working in the CHEMI-SEMI project holding a silicon wafer after atomic layer deposition, Department of Chemistry and Material Science
The project's goals are ambitious yet crucial. By innovating new chemical processes and materials, the team aims to minimize the environmental impact of semiconductor fabrication. This includes the development of novel, eco-friendly precursors and solvents, enhancing material purification, and advancing recycling practices, as highlighted by Dr. Marja Tiitta from Volatec.
Dr. Thomas Gädda of PiBond emphasizes the importance of collaborative efforts in achieving these sustainability targets, underscoring the project's reliance on a synergy of expertise from academia and industry. This collaborative framework is expected to yield advancements in chemical usage, process optimization, and energy efficiency in semiconductor manufacturing.
With its comprehensive approach, combining experimental research with computational modeling, the project aspires not only to innovate within the confines of semiconductor technology but also to set a new standard for environmentally conscious manufacturing practices in the industry.
Source: Significant Grant for Greener Semiconductor Technology from Business Finland | Aalto University