Low thermal budget n-type doping into Ge(001) surface using ultraviolet laser irradiation in phosphoric acid solution

作者：Takahashi Kouta^*; Kurosawa Masashi^*; Ikenoue Hiroshi; Sakashita Mitsuo; Takeuchi Wakana; Nakatsuka Osamu; Zaima Shigeaki

来源：Applied Physics Letters, 2016, 108(5): 052104.

DOI：10.1063/1.4941236

We have investigated phosphorus (P) doping into Ge(001) surfaces by using ultraviolet laser irradiation in phosphoric acid solution at room temperature. We demonstrated that the diffusion depth of P in Ge and the concentration of electrically activated P can be controlled by the number of laser shots. Indeed, a high concentration of electrically activated P of 2.4 x 10 19 cm(-3) was realized by 1000-times laser shots at a laser energy of 1.0 J/cm(2), which is comparable or better than the counterparts of conventional n-type doping using a high thermal budget over 600 degrees C. The generation current is dominant in the reverse bias condition for the laser-doped pn-junction diodes independent on the number of laser shots, thus indicating low-damage during the pn-junction formation. These results open up the possibility for applicable low thermal budget doping process for Ge-based devices fabricated on flexible substrates as well as Si electronics.

• 出版日期2016-2-1