| Due to their high Q and temperature-stable properties, quartz crystal oscillators are important clock sources in consumer, commercial, industrial, and military products for many years. The demand for quartz crystals and crystal oscillators has been increasing steadily between 4 and 10% annually since the ¡§dotcom¡¨ market collapse in 2000~2001. The total market for 2008 is expected to exceed $4.1B. The quartz crystal and crystal oscillator industry has made major progresses in miniaturization, performance enhancement, and cost reduction in the past ten years. The unique fabrication and encapsulation requirements though render quartz crystals and crystal oscillators difficult or close to impossible to be integrated onto the silicon-based IC platforms. The recent strong marketing push of the all silicon MEMS resonators and oscillators seemed to re-ignite the interest in displacing the quartz crystal technology and to open up again the prospect in clock source integration. Based on a 2006 review paper,[1] the author expands on the subject by reviewing the development of the all silicon MEMS oscillators and crystal oscillators in the past few years and commenting on what challenges they face in the highly competitive frequency control products industry. Since information on the technical development of the all silicon MEMS oscillators and crystal oscillators is abundantly and readily available, this paper addresses more on the market and business aspects. This paper also touches on the recent development of piezoelectric-activated silicon MEMS resonators and oscillators and all silicon oscillators (with no moving parts). |