反应动力学法评价MOCVD过程中金属前驱盐的稳定性（英文）

Evaluating the Thermostability of Metal Precursors in MOCVD by Reaction Kinetic Analysis

基于MOCVD法制备YBCO超导体过程中常用的、具有不同蒸发特性的3种金属前驱盐(Y(DPM)3,Cu(DPM)2,Ba(DPM)2),采用非等温热重分析法对比研究3种金属前驱盐在蒸发过程中的热稳定性和分解动力学特性,并依据典型动力学方法(Ozawa, Kissinger和Friedman法)获得各金属前驱盐在蒸发过程中的表观活化能(Ea)及其变化规律,进而分析其在蒸发过程中的热稳定性。结果表明:Ba(DPM)2金属前驱盐在蒸发过程中伴随发生热分解反应,且分解过程对温度变化敏感,而Y(DPM)3和Cu(DPM)2可以稳定蒸发。结合TGA-DSC分析证实,采用固相反应动力学方法来评价MOCVD过程中金属前驱盐的热稳定性是可靠的。

The sufficient and stable evaporation of metal precursors is crucial for obtaining reproducible YBa2Cu3O7-δ(YBCO) film with high quality in MOCVD technique. With the emergence of various metal precursors with high volatility, a practical way is needed to evaluate the thermal stability of metal precursors in evaporation. In this work, the thermal properties and decomposition kinetics of three precursors with different evaporation characteristics(Y(DPM)3, Cu(DPM)2, Ba(DPM)2) were comparatively investigated by non-isothermal thermogravimetric analysis, and the apparent activation energy(Ea) of evaporation process was obtained by the classic kinetic analysis methods(Ozawa, Kissinger and Friedman methods). The thermal stability of metal precursors in evaporation was evaluated through the change regulation of Ea during the heating process. The results show that the decomposition reaction of Ba(DPM)2 is indeed concomitant with its evaporation process and is highly sensitive to the change of temperature, while Y(DPM)3 and Cu(DPM)2 decompose stable. In addition, the consistent results of TGA-DSC and kinetic analysis can also confirm that evaporation kinetics study is reliable for investigating the thermostability of metal-organic compound in MOCVD process.