Homogenizing and Applying Dielectric Film to Wafer-Level Film Preparation

Abstract

MEMS devices such as piezoelectric devices are being used for various purposes in recent years. At the same time, silicon wafer diameters have been expanding for the purposes of mass production and cost reduction in the manufacture of these devices. Therefore, it is becoming more difficult to prepare a dielectric film with homogeneous thickness and electrical properties on the wafer. Generally, physical vapor deposition (PVD) methods such as sputtering are said to be comparatively reproducible for preparing films on large wafers, but these methods require expensive equipment. Metal organic decomposition (MOD), a chemical solution deposition (CSD) method, was used to form a PZT (Pb(Zr,Ti)O 3) film on the 4-inch wafers in this study because it does not need expensive equipment such as a vacuum system. To improve the ferroelectric properties of the film formed using the MOD method, we optimized the process parameters using design of experiments methods and found that temperature is the most significant control factor. A PZT film was prepared homogeneously on 4-inch wafers under optimum conditions. Furthermore, a more homogeneous PZT film was prepared by making the temperature uniform using a soaking cover. We think that these results can be applied to the preparation of films on larger wafers as an alternative to PVD methods, which are currently the main method of preparing dielectric films but which require expensive equipment.

Study on Homogeneous Wafer Level Dielectric Film Preparation Using Chemical Solution Deposition Method

“…[6][7][8][9][10][11][12] Crystallization temperature was quantitatively clarified to be most effective for the preparation of the high quality thin films in our previous work among our selected parameters. 13) The purpose of this study is to clarify the effects of the process parameters more preciously based on usage of larger orthogonal array and the other parameters that are familiar with temperature.…”