Baik Sung-Il, Kim Young-Woon
Research Institute of Advanced Materials, Department of Materials Science and Engineering, Seoul National University, 1 Gwanak-ro Gwanak-gu, Seoul, Republic of Korea.
Present address: Department of Materials Science & Engineering, Northwestern University, Evanston, IL, 60208, USA.
Appl Microsc. 2020 Feb 27;50(1):7. doi: 10.1186/s42649-020-00026-7.
Tantalum nitride (TaN) thin films were grown utilizing an inductively coupled plasma (ICP) assisted direct current (DC) sputtering, and 20-100% improved microhardness values were obtained. The detailed microstructural changes of the TaN films were characterized utilizing transmission electron microscopy (TEM), as a function of nitrogen gas fraction and ICP power. As nitrogen gas fraction increases from 0.05 to 0.15, the TaN phase evolves from body-centered-cubic (b.c.c.) TaN, to face-centered-cubic (f.c.c.) δ-TaN, to hexagonal-close-packing (h.c.p.) ε-TaN phase. By increasing ICP power from 100 W to 400 W, the f.c.c. δ- TaN phase becomes the main phase in all nitrogen fractions investigated. The higher ICP power enhances the mobility of Ta and N ions, which stabilizes the δ-TaN phase like a high-temperature regime and removes the micro-voids between the columnar grains in the TaN film. The dense δ-TaN structure with reduced columnar grains and micro-voids increases the strength of the TaN film.
利用电感耦合等离子体（ICP）辅助直流（DC）溅射生长氮化钽（TaN）薄膜，并获得了提高20%-100%的显微硬度值。利用透射电子显微镜（TEM）对TaN薄膜的详细微观结构变化进行了表征，该变化是氮气分数和ICP功率的函数。随着氮气分数从0.05增加到0.15，TaN相从体心立方（b.c.c.）TaN演变为面心立方（f.c.c.）δ-TaN，再演变为六方密堆积（h.c.p.）ε-TaN相。通过将ICP功率从100W增加到400W，f.c.c.δ-TaN相在所有研究的氮分数中成为主相。较高的ICP功率提高了Ta和N离子的迁移率，这像在高温状态下一样稳定了δ-TaN相，并消除了TaN薄膜中柱状晶粒之间的微孔。具有减少的柱状晶粒和微孔的致密δ-TaN结构提高了TaN薄膜的强度。
