Development and evaluation of a two-level functional structure for the thin film encapsulation

作者：Lee Jae Wung^*; Sharma Jaibir; Singh Navab; Kwong Dim Lee

来源：Journal of Micromechanics and Microengineering, 2013, 23(7): 075013.

DOI：10.1088/0960-1317/23/7/075013

This paper reports a two level capping structure for encapsulating micro-electro-mechanical system (MEMS) devices. The two level capping solves the main issue of the longer release time as well as safe sealing in thin film encapsulation (TFE). In this technique, the first cap layer has many etch holes, which were uniformly distributed on it to enhance the removal of the sacrificial layer. The second cap layer forms a cap on every etch hole in the first cap layer to protect the mass loading on MEMS devices. This technique was found to be very effective in reducing the release time of the TFE. For the 1200 mu m x 1200 mu m sized cavity encapsulation, this technique decreases the release time of the TFE by a factor of 24 in comparison to the sidewall located channel scheme. The presented technique also helps in reducing the size of TFE as the etch holes are uniformly distributed on the TFE itself. Wide seal rings were not required to accommodate sidewall channels.

• 出版日期2013-7