Porous film getter structure and preparation method thereof

Abstract

The invention discloses a porous film getter structure. Theporous film getter structure comprises a wafer and a film getter, the upper surface of the wafer is provided with a groove structure, the inner wall of the groove structure is of a porous structure, and the porous structure is covered with the film getter. The invention further discloses a preparation method of the structure, dry or wet etching is combined with gold particle auxiliary etching to form the three-dimensional film getter structure, and the porous structure is prepared on the prepared groove structure to increase the deposition area and deposition volume of the film getter, so that the getter performance of the film getter is effectively improved, and the service life of the film getter is effectively prolonged. The gold film deposited through the evaporation-stripping process can form uniformly distributed gold particles on the side wall and the substrate of the groove under the process condition of high-temperature rapid annealing, the annealed gold particles are used for carrying out the etching process, uniformly distributed porous structures are etched on the side wall, the adhesion of the getter film, the side wall and the bottom substrate is further improved, and the phenomena of falling of the getter, device damage and the like are avoided.

Description

technical field [0001] The invention belongs to the field of high-vacuum MEMS device packaging, and specifically relates to a porous film getter structure and a preparation method thereof. Background technique [0002] At present, the requirements for the internal vacuum degree and service life of devices in the field of high-vacuum MEMS packaging are getting higher and higher, especially the electronic devices are getting closer to miniaturization, so how to maintain a high vacuum degree and Service life has become a technical difficulty. In today's electronic packaging field, the most common vacuum maintenance method is to evaporate a thin film getter inside the electronic device. The characteristic of the thin film getter is to continuously absorb the residual gas, infiltrating gas and residual adsorbed gas inside the cavity. . So as to meet the requirement of maintaining the vacuum degree inside the electronic device. [0003] The getter performance of thin film gette...

AI Technical Summary

Problems solved by technology

At present, there are related patents to increase the deposition area of ​​the getter by preparing a vertical three-dimensional structure of bumps and grooves inside the cavity. First, the simple concave-convex structure designed by this patent has a limited increase in the deposition area of ​​the getter.

In addition, the three-dimensional structure of bumps and grooves is weak, and the most critical thing is that the thin film getter deposited on the smooth side wall has weak adhesion to the side wall, and the weak adhesion of the film to the side wall is very easy to make During the use of the device, the thin film getter falls off, contaminates the inside of the device, and causes the performance of the thermal unit of the device to decline or even fail. Moreover, the three-dimensional getter structure prepared by the related patent has no attachment support structure, and it is easy to break and collapse. Therefore The practicability of this patent is weak and it is difficult to be used in actual production

In the prior art, there is a silicon processing technology that directly deposits gold particles to form a porous structure on the wafer, but it can only deposit gold particles directly on the flat substrate of the wafer, so this process can basically only etch the surface of the wafer substrate, absorbing The increase of the aerosol structure is still limited, and the density of directly deposited gold particles will form a very dense porous structure on the surface of the substrate. When the porous structure is too dense, the porous structure at the bottom is easy to break and collapse. Therefore, the application of this technology Very limited

Images