Baron Filipp A, Mikhlin Yurii L, Molokeev Maxim S, Rautskiy Mikhail V, Tarasov Ivan A, Volochaev Mikhail N, Shanidze Lev V, Lukyanenko Anna V, Smolyarova Tatiana E, Konovalov Stepan O, Zelenov Fyodor V, Tarasov Anton S, Volkov Nikita V
Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Krasnoyarsk 660036, Russia.
Institute of Chemistry and Chemical Technology, Federal Research Center KSC SB RAS, Krasnoyarsk 660036, Russia.
ACS Appl Mater Interfaces. 2021 Jul 14;13(27):32531-32541. doi: 10.1021/acsami.1c08036. Epub 2021 Jun 28.
Copper-doped titanium oxynitride (TiNO) thin films were grown by atomic layer deposition (ALD) using the TiCl precursor, NH, and O at 420 °C. Forming gas was used to reduce the background oxygen concentration and to transfer the copper atoms in an ALD chamber prior to the growth initiation of Cu-doped TiNO. Such forming gas-mediated Cu-doping of TiNO films had a pronounced effect on their resistivity, which dropped from 484 ± 8 to 202 ± 4 μΩ cm, and also on the resistance temperature coefficient (TCR), which decreased from 1000 to 150 ppm °C. We explored physical mechanisms causing this reduction by performing comparative analysis of atomic force microscopy, X-ray photoemission spectroscopy, X-ray diffraction, optical spectra, low-temperature transport, and Hall measurement data for the samples grown with and without forming gas doping. The difference in the oxygen concentration between the films did not exceed 6%. Copper segregated to the TiNO surface where its concentration reached 0.72%, but its penetration depth was less than 10 nm. Pronounced effects of the copper doping by forming gas included the TiNO film crystallite average size decrease from 57-59 to 32-34 nm, considerably finer surface granularity, electron concentration increase from 2.2(3) × 10 to 3.5(1) × 10 cm, and the electron mobility improvement from 0.56(4) to 0.92(2) cm V s. The DC resistivity versus temperature () measurements from 4.2 to 300 K showed a Cu-induced phase transition from a disordered to semimetallic state. The resistivity of Cu-doped TiNO films decreased with the temperature increase at low temperatures and reached the minimum near = 50 K revealing signatures of the quantum interference effects similar to 2D Cu thin films, and then, semimetallic behavior was observed at higher temperatures. In TiNO films grown without forming gas, the resistivity decreased with the temperature increase as () = - 1.88 + 604 μΩ cm with no semimetallic behavior observed. The medium range resistivity and low TCR of Cu-doped TiNO make this material an attractive choice for improved matching resistors in RF analog circuits and Si complementary metal-oxide-semiconductor integrated circuits.
采用原子层沉积（ALD）法，以TiCl前驱体、NH和O为原料，在420℃下生长掺铜氮氧化钛（TiNO）薄膜。在掺铜TiNO生长开始之前，使用形成气体来降低背景氧浓度，并在ALD腔室中转移铜原子。这种通过形成气体介导的TiNO薄膜铜掺杂对其电阻率有显著影响，电阻率从484±8降至202±4μΩ·cm，对电阻温度系数（TCR）也有显著影响，TCR从1000降至150ppm/℃。我们通过对有和没有形成气体掺杂生长的样品进行原子力显微镜、X射线光电子能谱、X射线衍射、光谱、低温输运和霍尔测量数据的对比分析，探索了导致这种降低的物理机制。薄膜之间的氧浓度差异不超过6%。铜偏析到TiNO表面，其浓度达到0.72%，但其穿透深度小于10nm。通过形成气体进行铜掺杂的显著效果包括TiNO薄膜微晶平均尺寸从57 - 59nm减小到32 - 34nm，表面粒度显著更细，电子浓度从2.2(3)×10增加到3.5(1)×10cm，电子迁移率从0.56(4)提高到0.92(2)cm²/V·s。在4.2至300K范围内的直流电阻率与温度（）测量结果表明，铜诱导了从无序到半金属态的相变。掺铜TiNO薄膜的电阻率在低温下随温度升高而降低，并在 = 50K附近达到最小值，显示出与二维铜薄膜类似的量子干涉效应特征，然后在较高温度下观察到半金属行为。在没有形成气体的情况下生长的TiNO薄膜中，电阻率随温度升高而降低，表达式为（） = - 1.88 + 604μΩ·cm，未观察到半金属行为。掺铜TiNO的中等范围电阻率和低TCR使其成为用于射频模拟电路和硅互补金属氧化物半导体集成电路中改进匹配电阻器的有吸引力的选择。
