W-Ti-N薄膜的制备及其热稳定性

Preparation of W-Ti-N thin film and its thermal stability

以W-10%Ti二元合金靶材为原材料,采用直流磁控溅射法在Si基体上制备了W-Ti-N三元薄膜,研究了N2分压和溅射功率对薄膜相结构和N含量的影响;在W-Ti-N/Si结构的基础上制备了Cu/W-Ti-N/Si多层结构,并对其在不同的温度下进行真空热处理。结果表明:通过调整N2分压和溅射功率,即N2/Ar比为1∶3且功率为70 W时可以获得非晶态W-Ti-N薄膜。薄膜在700℃以下热处理时具有非常好的热稳定性,方块电阻小于0.6Ω/□,略高于退火前的0.285Ω/□。但退火温度超过700℃后,稳定性迅速下降,在800℃退火后方块电阻达到170Ω/□。Cu布线用W-Ti-N非静态薄膜扩散阻挡层退火过程中的失效机理主要为元素间的界面扩散及反应。

W-Ti-N thin films were deposited by DC magnetron sputtering on Si substrates with the W-10%Ti alloy target,and the effects of N2pressure and sputtering power on the phase structure and N content of the films were studied.Then the Cu/W-Ti-N/Si muhilayer structure was fabricated on the basis of W-Ti-N/Si structure,and vacuum heat treatment was carried out at different temperatures.The results show that the amorphous W-Ti-N films can be obtained with N2/Ar ratio 1:3and the sputtering power 70W.The film has very good thermal stability when heat treated below 700℃.Meanwhile,the square resistance of it is less than 0.6Ω/□,which slightly,higher than 0.285Ω/□ before annealing.But the Cu film tends to agglomerate when the temperature is above 700℃ and the square resistance reached 170Ω/□ after annealing at 800℃.A failure mechanism of the diffusion barrier is proposed based on the thermal stress and interface reaction.