Plasma treatment with plasma cleaner improves the stability of SiO2 film electret:
Surface treatment of the thermally grown SiO2 film on the silicon substrate with plasma plasma of the plasma cleaner improves the storage stability of the electret charge of the silicon dioxide film.
Organic polymer electret materials have good charge storage stability. At present, most electret sensors on the market are organic polymer electret film sensors. Although such sensors have the advantages of long life, thin-film type, and low cost, they are discrete devices with large volumes and cannot meet the requirements of miniaturization and integration of electret acoustic sensors.
In recent years, it has been found that silicon dioxide (SiO2) film has better electret performance. In view of its important position in silicon integrated circuit technology, people hope that SiO2 film can become a sensitive film material for the preparation of micro-integrated acoustic sensors.

However, the electret charge of the SiO2 film is easily lost at higher temperatures, and the SiO2 film has good hydrophilicity, so that its surface conductance increases sharply with the increase of environmental humidity, resulting in storage on the surface of the SiO2 film and near The electret charge on the surface is easily attenuated, which restricts the development of miniature integrated acoustic sensors.
In order to solve this problem, many scholars have spent nearly 10 years studying two methods to improve the storage charge stability of silicon dioxide film electrets.
First, in the early 1990s, a chemical correction method proposed by a Dutch scholar,