Wafer bonding for microsystems technologies

In microsystems technologies, frequently complex structures consisting of s tructured or plain silicon or other wafers have to be joined to one mechani cally stable configuration. In many cases, wafer bonding, also termed fusio n bonding, allows to achieve this objective. The present overview will intr oduce the different requirements surfaces have to fulfill for successful bo nding especially in the case of silicon wafers. Special emphasis is put on understanding the atomistic reactions at the bonding interface. This unders tanding has allowed the development of a simple low temperature bonding app roach which allows to reach high bonding energies at temperatures as low as 150 degrees C. Implications for pressure sensors will be discussed as well as various thinning approaches and bonding of dissimilar materials. (C) 19 99 Elsevier Science S.A. All rights reserved.