一种用于金刚石膜沉积装置的重入式微波谐振腔

A reentrant microwave cavity for MPCVD to prepare diamond films

微波等离子体化学气相沉积法(MPCVD)是制备高品质金刚石膜的重要方法,而MPCVD技术的关键是其设备核心部件谐振腔的设计。本文基于目前广泛应用的圆柱式和椭球式两种MPCVD谐振腔中微波传输的特点和其各自的优点,提出了一种重入式微波谐振腔的设计构想,并利用数值模拟的方法对这一构想进行了验证。模拟的结果表明,微波在重入式微波谐振腔内外壁之间的路径传输后,可在金刚石膜沉积台处形成一最强且相对均匀的电场。在相同的输入功率下,其形成的最大电场强度高于圆柱式和椭球式两种谐振腔时的情况。由于重入式的微波谐振腔具有结构简单、频率易于调节的优点,因而这一构想可为设计制造新型的MPCVD金刚石膜沉积设备提供参考依据。

Microwave plasma chemical vapor deposition（MPCVD） is of importance to preparing the high-quality diamond films,where the design of the cavity as its core part is a key factor.A reentrant microwave cavity was therefore proposed according to the wave transmission performance and advantages of cylindrical and ellipsoidal cavities which are widely used at present,and its conceptual design was verified via a numerical simulation.The results showed that the microwave is transmitted through the gap between the inner and outer cylindrical walls of reentrant microwave cavity,then a highestintensity electric field forms on the substrate in relatively uniform distribution,and the intensity of the electric field is found higher than that in either cylindrical or ellipsoidal cavity under the same input power.Advantages of such a reentrant microwave cavity are simple in construction and easy to regulate frequency,thus making its conceptual design available to be a theoretical reference for designing new deposition system in MPCVD to prepare diamond films.