Silicon-to-glass anodic bonding is performed at temperatures below 180°C using lithium aluminosilicate-β-quartz glass ceramic. High alkaline ion mobility at low temperature, which is required for bonding, and thermal expansion coefficient matching to Si are realized by controlling the composition of the glass ceramic. Bonding is obtained at a lowest temperature of 140°C. Useful bonding conditions are temperature above 160°C (applied voltage above 500 V). Since the etch rate of the glass ceramic is five times higher than that of Pyrex glass in HF wet etching and the undercut is very small with a Cr-Au etch mask, three-dimensional structures are easily fabricated. Low-temperature anodic bonding using this type of glass ceramic is useful for the packaging and assembling of MEMS.
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