Moto Kenta, Yoshimine Ryota, Suemasu Takashi, Toko Kaoru
Institute of Applied Physics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8573, Japan.
JSPS Research Fellow, 8 Ichiban-cho, Chiyoda-ku, Tokyo, 102-8472, Japan.
Sci Rep. 2018 Oct 4;8(1):14832. doi: 10.1038/s41598-018-33161-z.
To improve the performance of electronic devices, extensive research efforts have recently focused on the effect of incorporating Sn into Ge. In the present work, we investigate how Sn composition x (0 ≤ x ≤ 0.12) and deposition temperature T (50 ≤ T ≤ 200 °C) of the GeSn precursor affect subsequent solid-phase crystallization. Upon incorporating 3.2% Sn, which is slightly above the solubility limit of Sn in Ge, the crystal grain size increases and the grain-boundary barrier decreases, which increases the hole mobility from 80 to 250 cm/V s. Furthermore, at T = 125 °C, the hole mobility reaches 380 cm/V s, which is tentatively attributed to the formation of a dense amorphous GeSn precursor. This is the highest hole mobility for semiconductor thin films on insulators formed below 500 °C. These results thus demonstrate the usefulness of Sn doping of polycrystalline Ge and the importance of temperature while incorporating Sn. These findings make it possible to fabricate advanced Ge-based devices including high-speed thin-film transistors.
为了提高电子器件的性能，最近大量的研究工作集中在将锡掺入锗的效果上。在本工作中，我们研究了锗锡前驱体的锡成分x（0≤x≤0.12）和沉积温度T（50≤T≤200°C）如何影响随后的固相结晶。掺入3.2%的锡，略高于锡在锗中的溶解度极限，晶粒尺寸增加且晶界势垒降低，空穴迁移率从80 cm²/V·s增加到250 cm²/V·s。此外，在T = 125°C时，空穴迁移率达到380 cm²/V·s，这初步归因于形成了致密的非晶锗锡前驱体。这是在500°C以下形成的绝缘体上半导体薄膜的最高空穴迁移率。因此，这些结果证明了多晶锗锡掺杂的有用性以及掺入锡时温度的重要性。这些发现使得制造包括高速薄膜晶体管在内的先进锗基器件成为可能。
