Patent ID: 8119431

Claim:
A method of forming a micro-electromechanical system (MEMS) comprising: providing a cap substrate; providing a support substrate; depositing a conductive material over the support substrate; patterning the conductive material to leave a conductive portion that forms a gap stop and a contact, wherein the gap stop is separated form the contact by an opening; forming a bonding material over the contact and in the opening, wherein the gap stop and the contact prevent the bonding material from extending outside the opening; and attaching the cap substrate to the support substrate by the step of forming the bonding material; wherein forming the bonding material comprises: forming a semiconductor layer over the conductive material; and heating the cap substrate and the semiconductor layer to form the bonding material and bond the cap substrate to the support substrate; and further comprising forming a stack over the conductive material wherein the step of forming the semiconductor layer is part of the step of forming the stack; wherein the step of forming the stack over the conductive portion further comprises: forming a seed layer comprising silicon over the conductive portion; and forming a first layer comprising silicon and germanium over the seed layer; and wherein the step of forming the semiconductor layer further comprises forming a second layer comprising germanium over the first layer.