MEMS technology is the primary direction and core foundation of sensor technology development

and process residual stress is a key factor affecting the performance stability of MEMS sensors.Plasma enhanced chemical vapor deposition(PECVD)has the characteristics of low process temperature and low film stress

and it acts as the mainstream passivation protection process for MEMS chips.In SiO

2

/Si

3

N

4

multi-layer film systems

stress mismatch is a critical factor affecting the performance stability of film devices such as MEMS micro-hotplates.Through research on process parameters including process temperature

chamber pressure

gas fl

ow

and radio frequency power

stress matching of the multi-layer film is achieved.The minimum absolute stress value of the SiO

2

/Si

3

N

4

composite film reaches 16MPa

meeting the process requirements for MEMS flow sensor chips.