Disclosed is a MEMS device having lower and upper chambers with a similar pressure and/or a similar gaseous chemistry. The MEMS device includes a top MEMS plate and a bottom MEMS plate. The MEMS device also includes a lower chamber between the bottom MEMS plate and the top MEMS plate, and an upper chamber between the top MEMS plate and a sealing layer. The top MEMS plate includes at least one segment that is narrower than the bottom MEMS plate, thereby causing the lower and upper chambers to have a similar pressure and/or a similar gaseous chemistry. In another implementation, the top MEMS plate has at least one through-hole, thereby causing the lower and upper chambers to have a similar pressure and/or a similar gaseous chemistry.