Bonding of Si Chips

Anodic bonding of Si to Pyrex was commonly used to create a sealed Si chip [1,281,442,820,836]. Various bonding conditions used are summarized in Table 2.2. A positive voltage is applied on the Si wafer with respect to that of the Pyrex wafer (negative) [91,92,281]. 

If anodic bonding between glass and Si fails (due to a thick oxide layer [1 im] on Si or platinum electrode on Si), a low-melting spin-on-glass (SOG) can be applied as an adhesive. SOG, which is a methylsilsesquioxane polymer, flows very well at the temperature between 150°C and 210°C, and therefore it fills the grooves (i.e., around the Pt electrodes) for effective bonding [93]. 

Bonding of Si to glass was also achieved using UV-curable optical adhesives. Benzocyclobutene has been used to bond Si and Pyrex [94-99,942]. 

Various Conditions of Anodic Bonding of Si and Pyrex Plates 

On the other hand, bonding of Si to Si was achieved by a low-temperature curing polyimide film [100], or by using an intermediate deposited layer of borophosphosilicate glass and subsequent anodic bonding (300 V, 350°C) [101]. 

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