An optimized process of high-performance integrated passive devices (IPDs) on SI-GaAs substrate for RF applications

An integrated passive device (IPD) technology by semi-insulating (SI) GaAs-based fabrication has been developed to meet the ever increasing needs of size and cost reduction for RF and microwave applications. In this paper, we develop an advanced optimized process for realizing IPDs to reduce fabrication time and total cost and to increase RF performances. The critical characteristics of lumped elements thin film resistor (TFR), spiral inductor and metal-insulator-metal (MIM) capacitor are optimized in this advanced process. A low-pass filter (LPF) for global system for mobile communications (GSM) is demonstrated by using this IPD process; it shows very good RF performances in spite of its small chip size and low cost, when compared with the recently reported literature.

I. Introduction

Growing demand for mobile and wireless communication systems has generated a lot of interest in low-cost, high-quality fabrication technologies. Owing to the fact that IPDs are generally fabricated using standard wafer fabrication technologies such as thin film and photo-lithography processing, they can be manufactured with these advantages and widely used in front-end RF sections of mobile phone [1]. IPDs which contain passive circuit components such as resistors, inductors, and capacitors are totally integrated and mounted on a semiconducting substrate [2]. IPDs can be applied to existing fields of applications, which use whole passive devices, and have already been applied to the front end modules (FEMs) of mobile systems. In addition, in mobile phone communication system, many functional blocks such as filters, baluns, diplexers, and power combiners/dividers can be realized by IPD technology [3]–[5].