Micro-Oven-Controlled MEMS Oscillator Integrated with Micro-Evaporator for Frequency Trimming

We report on a near-zero temperature drift MEMS oscillator that is integrated with aluminum micro-evaporators to achieve 400 ppm post-packaging permanent frequency trimming for the first time. The resonator is degenerately doped with phosphorous and micro-oven controlled to achieve a frequency instability of ±2.6 ppm over a temperature range of −40 °C to 85 °C, which increases slightly to ±3.0 ppm after 400-ppm permanent trimming by local evaporation of Al.

Introduction

MEMS resonators have been widely researched as a replacement for quartz crystal oscillators in timing and communication applications [1] [2]. Compared to quartz crystal oscillators, MEMS oscillators are small-scale, low cost, and allow for high-volume manufacturing and integration.