Doped diamond coating could enhance electronics

A new method for creating thin films of diamonds may allow manufacturers to enhance future electronics.

In industrial settings, diamonds are particularly valued for their hardness, optical clarity, smoothness, and resistance to chemicals, radiation and electrical fields.

For electronics applications, researchers dope diamonds in order to make them conductive, introducing the semiconductor boron into the diamond manufacturing process.

It has previously been a challenge to imbue electronic devices with diamond-like qualities by applying a doped diamond coating, or thin film because the high temperatures required to apply a doped diamond thin film would destroy sensitive electronics, including biosensors, semiconductors, and photonic and optical devices.

In a paper published in Applied Physics Letters, a team of researchers at Advanced Diamond Technologies in Romeoville, Illinois report creating thin films of boron-doped diamond at temperatures low enough (between 460-600°C) to coat many of these devices.

While low-temperature deposition of boron-doped diamond thin films is not conceptually new, the research team found no evidence in the literature of such diamond films that had both sufficient quality and manufacturing rates fast enough to be commercially useful.

Tweaking their own normal-temperature boron doping recipe by both lowering the temperature and adjusting the typical ratio of methane to hydrogen gas yielded a high quality film without appreciable change in conductivity or smoothness compared to diamond films made at higher temperatures.

The researchers said more data and study is needed to better understand low-temperature opportunities. Even so, by further optimizing the recipe, the researchers expect to be able to deposit boron-doped diamond thin films at temperatures even lower than 400° C.

In a statement Hongjun Zeng of Advanced Diamond Technologies said, ‘The lower the deposition temperature, the larger number of electronic device applications we can enable

‘That will further expand the product categories for thin, smooth, conductive diamond coatings.’