2, Frontier Research Academy for Young Researchers, Kyushu Institute of Technology, Fukuoka, Kitakyushu, Japan
1, Advanced Power Electronics Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Osaka, Osaka, Japan
Diamond is a wide bandgap material with extreme thermal, electrical and optical properties that receives unprecedented attention since it is expected to handle more power with higher efficiency than conventional semiconductors. However, due to the intrinsic difficulties, device fabrication has serious problems in achieving n-type doping under good conditions. Moreover, diamond is not easily modified like other semiconducting materials that can be treated thermally after deposition.
Recently laser-induced doping has been applied to other wide band gap semiconductor (SiC) and its effectivity is experimentally proved. In this work, we applied laser-induced doping to singlecrystalline diamond, for the first time to our knowledge. The doping of phosphorus and Boron into singlecrystalline diamond is discussed from the chemical compositionally and electrically viewpoints.
In this work, Singlecrystalline diamond (100) plate (Ib) was immersed in a phosphoric acid solution (85%) and Boric Acid. ArF excimer laser (Gigaphoton Inc. wavelength: 193 nm) beams were irradiated on it. The laser beam irradiation was carried out at a frequency of 1 Hz and at different laser fluences up to 3.9 J/cm2.
The results indicate that SC diamond hardly damaged on the plate surface by optical images even at a maximum fluence of 3.9 J/cm2. Electrically, the electrical conductivity increases with increasing fluence and number of laser shots. Moreover, Phosphorus depth profile was investigated by Secondary-Ion Mass Spectrometry (SIMS), in which the Incorporation of Phoshporus up to 30 nm was achieved by increasing number of shots and reducing time interval between successive shots.
Further systematic experiments are conducted, such as Raman, I-V meaurements, and theoretical simulations, results will be reported at the conference.
This study was partially supported by JSPS KAKENHI Grant Numbers: JP15H04127, JP16K14391, and JSPS Fellow Grant JP17F17380.