Hydrogen Fluoride

Hydrogen fluoride is essential to the semiconductor process, and we were reminded of this by the recent trade dispute with Japan. In the following, we’ll find out just what hydrogen fluoride is, and what roles it plays in the semiconductor manufacturing process. Hydrogen fluoride: Indispensable to semiconductor processes

Hydrogen fluoride, also known as ‘etching gas’, is a compound created by the bonding of a hydrogen (H) atom with a fluorine (F). Essentially a fluorine atom bonded to hydrogen, HF is highly reactive and can melt glass or plastic. HF has a boiling point of 19.5°C, and exists as a gas at room temperature (25°C). However, it can be easily liquefied under pressure or at sufficiently cool temperatures. HF is also highly water soluble. An aqueous solution of HF is known as hydrogen fluoride, or fluorhydric acid. The Role of HF in Semiconductor Processes HF is used in the ‘etching’ and ‘cleaning’ steps of the semiconductor process. Let’s see what the role of HF is in each.

First, in the etching step, the role of HF can be described as ‘printmaking’. Printmaking involves printing a drawing into a wooden surface, then using a carving knife to carve out the non-drawing portions of the surface. HF works like a carving knife, scraping away the unnecessary parts of a wafer. HF also has a use in the cleaning step. Even the tiniest impurity can be critical to a semiconductor, damaging circuits and slowing performance. A cleansing step is necessary to wash away any residual foreign matter. HF is used as the cleaning solution. Semiconductors are becoming more and more integrated, and minimizing defect rates calls for ultra-pure HF. It’s obvious that HF plays a huge role in ensuring semiconductor performance. While HF was dependent on imports in the past, domestic suppliers have started producing hydrogen fluoride as well. Remember, every advance in semiconductor technology is accompanied by similar advances in the materials used for semiconductor processes. More Related Content ‘Ultrapure Water’: Flawless Water for Flawless Semiconductors