CN102169038B

CN102169038B - Side wall protection method for MEMS (Micro Electronic Mechanical System) silicon capacitive pressure transducer with sandwich structure

Info

Publication number: CN102169038B
Application number: CN201110003525A
Authority: CN
Inventors: 朱健; 贾世星; 侯智昊; 吴璟; 黄镇
Original assignee: CETC 55 Research Institute
Current assignee: CETC 55 Research Institute
Priority date: 2011-01-10
Filing date: 2011-01-10
Publication date: 2012-10-10
Anticipated expiration: 2031-01-10
Also published as: CN102169038A

Abstract

The invention provides a side wall protection method for an MEMS (Micro Electronic Mechanical System) silicon capacitive pressure transducer with a glass-silicon-glass or silicon-silicon-glass sandwich structure, which is a process method for preventing a capacitance gap from being polluted by dust and water in the manufacturing technical process of the transducer. The method is characterized in that an auxiliary side wall is introduced in front of an air guide hole in the manufacturing process of the MEMS capacitive pressure transducer to prevent dust and water from entering the capacitance gap in the technical process; and a silicon nitride membrane is arranged between the auxiliary side wall and bottom layer glass to prevent the auxiliary side wall from being bonded with the bottom layer glass and automatically separate the side wall from a chip after the chip is separated. The method has the advantages that the auxiliary side wall is introduced in front of the air guide hole, so that dust and water are effectively prevented from entering the capacitance gap in the technical process; and the silicon nitride membrane is arranged between the auxiliary side wall and the bottom layer glass, so that the auxiliary side wall is prevented from being bonded with the bottom layer glass, the side wall is automatically separated from the chip after the chip is separated, and the reliability and the yield of the capacitive pressure transducer are enhanced.

Description

Be used for sandwich structure MEMS silicon capacitive pressure transducer side wall protection method

Technical field

What the present invention relates to is a kind of MEMS capacitance pressure transducer, side wall protection method that is used for glass-silicon-glass or silicon-silicon-glass sandwich structure.Specifically a kind of process that is used for preventing that sandwich structure MEMS capacitance pressure transducer, manufacture craft process dust, water from polluting capacitance gap.Belong to MEMS capacitance pressure transducer, manufacture technology field.

Background technology

Dust and water in the manufacture craft process of the sandwich structure silicon MEMS capacitive pressure transducer that glass-silicon-glass or silicon-silicon-glass three-decker is formed are to influence the reliability of this sensor and the principal element of yield rate.Dust in the technological process and water can get into capacitance gap through gas port, and get into the dust and the water of capacitance gap, are difficult in to remove after accomplishing technology.And then influence the reliability and the yield rate of Silicon Pressure Sensor of Capacitance.

Summary of the invention

What the present invention proposed is a kind of MEMS capacitance pressure transducer, side wall protection method that is used for glass-silicon-glass or silicon-silicon-glass sandwich structure.Its purpose is intended to stop in glass-silicon-glass or silicon-silicon-three layers of Silicon Pressure Sensor of Capacitance manufacture craft of the glass process dust, water to get into capacitance gap.

Technical solution of the present invention: it is characterized in that in MEMS capacitance pressure transducer, manufacturing process; Before gas port, introduce auxiliary side wall; Be used for stoping at technological process dust, water getting into capacitance gap, between auxiliary side wall and the bottom glass silicon nitride film be set, prevent auxiliary side wall and bottom glass bonding; Make after chip separates, side wall breaks away from chip automatically.

Advantage of the present invention: owing to before gas port, introduce auxiliary side wall; Dust, water entering capacitance gap in technological process have been stoped effectively; Owing between auxiliary side wall and bottom glass, silicon nitride film is set; Prevent auxiliary side wall and bottom glass bonding, make after chip separates that side wall breaks away from chip automatically.Thereby the reliability and the yield rate of Silicon Pressure Sensor of Capacitance have been improved.

Description of drawings

Fig. 1 is that Silicon Pressure Sensor of Capacitance side wall and chip break away from front cross sectional view.

Fig. 2 is that Silicon Pressure Sensor of Capacitance side wall and chip break away from the back cut-open view.

Fig. 3 is bottom glass and top electrode synoptic diagram thereof.

Fig. 4 is silicon structure bottom surface and bottom surface cavity synoptic diagram.

Fig. 5 is silicon structure end face and apex cavity synoptic diagram.

Fig. 6 is the three-decker synoptic diagram.

Among the figure 1 is top layer glass, the 2nd, and the responsive silicon fiml structure of capacitance pressure transducer,, the 3rd, bottom glass, the 4th, the electrode of electric capacity and bond pad, the 5th, the silicon nitride film structure, the 6th, vacuum cavity, the 7th, capacitance gap, the 8th, gas port, the 9th, silicon is assisted side wall.

Embodiment

Contrast accompanying drawing 1; Its structure is that 2 on the responsive silicon fiml structure of top layer glass 1 and capacitance pressure transducer, is a top layer glass 6; On the bottom glass 3 electrode and the bond pad 4 of electric capacity; Be the auxiliary side wall of introducing 9 of silicon before the gas port 8, between auxiliary side wall 9 of silicon and the bottom glass 3 silicon nitride film structure 5 be set, the responsive

silicon fiml structure

2 and 5 on the silicon nitride film structure of capacitance pressure transducer, are capacitance gaps 7.

In glass-silicon-glass or silicon-silicon-three layers of MEMS capacitance pressure transducer, of glass manufacturing process; Before gas port 8, introduce the auxiliary side wall 9 of silicon; Be used for stoping at technological process dust, water getting into capacitance gap 7, between auxiliary side wall 9 of silicon and the bottom glass 3 silicon nitride film structure 5 be set, prevent auxiliary side wall 9 of silicon and bottom glass 3 bondings; Make after chip separates, the auxiliary side wall 9 of silicon breaks away from chip (like Fig. 2) automatically.

Contrast accompanying drawing 3 in the process of making bottom glass and top electrode thereof, is made silicon nitride film structure 5, is used for stoping anodic bonding process, between auxiliary side wall 9 of silicon and the bottom glass 3 bonding takes place;

Contrast accompanying drawing 4 in making the silicon structure process, utilizes ICP or wet-etching technology, makes the auxiliary side wall 9 of silicon in responsive silicon fiml structure 2 bottom surfaces of capacitance pressure transducer,, is used for stoping in technological process, and dust or water are to the pollution of capacitance gap 7; After accomplishing bonding technology, disk is carried out scribing.In scribing processes, the control scribing degree of depth keeps auxiliary side wall 9 structures of silicon, and is as shown in Figure 1, makes the auxiliary side wall 9 of silicon continue in scribing processes to prevent that dust, water from getting into capacitance gap 7.After accomplishing scribing, when carrying out disk sliver, separating chips since the auxiliary side wall 9 of silicon not with bottom glass 3 bondings; The auxiliary side wall 9 of silicon is under the stress of chip division; Automatically separate with chip, like Fig. 2, shown in Figure 6, the realization gas port is communicated with extraneous gas.

Glass-silicon-glass or silicon-silicon-glass three-decker silicon MEMS capacitance pressure transducer, is the pressure sensor structure that a kind of precision is high, sensitivity is good, long-time stability are good; Mainly realize through dried wet-etching technology, metallization process, glass-silicon-glass or silicon-silicon-three layers of bonding technology of glass; In technological process, have the advantage that technology is simple, be prone to realization, be widely used in fields such as meteorology, vacuum meter, altitude gauge.

Claims

1. MEMS capacitance pressure transducer, side wall protection method that is used for glass-silicon-glass or silicon-silicon-glass sandwich structure; It is characterized in that between the responsive silicon fiml structure of the first top layer glass and capacitance pressure transducer, be the second top layer glass; Bottom is on glass to be the electrode and the bond pad of electric capacity; It before the gas port the auxiliary side wall of introducing of silicon; Between auxiliary side wall of silicon and the bottom glass the first silicon nitride film structure being set, is capacitance gap between the responsive silicon fiml structure of capacitance pressure transducer, and the second silicon nitride film structure; In the capacitance pressure transducer, manufacturing process; Before gas port, introduce the auxiliary side wall of silicon; Be used for stoping at technological process dust, water getting into capacitance gap, between auxiliary side wall of silicon and the bottom glass the first silicon nitride film structure be set, prevent auxiliary side wall of silicon and bottom glass bonding; Make after chip separates, the auxiliary side wall of silicon breaks away from chip automatically; In the process of making bottom glass and top electrode thereof, make the first silicon nitride film structure, be used for stoping anodic bonding process, bonding takes place between auxiliary side wall of silicon and the bottom glass; In making the silicon structure process, utilize ICP or wet-etching technology, make the auxiliary side wall of silicon in the responsive silicon fiml structure bottom surface of capacitance pressure transducer,, be used for stoping in technological process, dust or water are to the pollution of capacitance gap; After accomplishing bonding technology, disk is carried out scribing; After accomplishing scribing, when carrying out disk sliver, separating chips since the auxiliary side wall of silicon not with bottom glass bonding, the auxiliary side wall of silicon separates with chip under the stress of chip division automatically, realizes being communicated with of gas port and extraneous gas.