化学表面处理对热生长氧化形成的SiO2驻极体电荷寿命的影响

以实验结果为依据研究了化学表面处理对ＳｉＯ＿２薄膜驻极体内电荷储存稳定性的影响。得知用ＨＭＤＳ或ＤＣＤＭＳ等有机试剂进行的化学表面处理将在ＳｉＯ＿２驻极体表面形成一个疏水的保护层。通常情况下，它将起到防止外界环境中的水吸附而形成的表面导电结构，对改善这一驻极体薄膜的电荷储存稳定性起到显著的作用；伴随着驻极体内长久电荷的捕获储存，在驻极体内发生的电化学反应将有水分子生成，而用化学表面处理后形成的疏水保护层有时也会阻止驻极体内部过剩的水分子向外扩散，造成用化学表面处理后驻极体内的电荷较快衰减这一反常现象的发生。

THE INFLUENCE OF CHEMICAL SURFACE MODIFICATION ON CHARGE STORAGE STABILITY IN THE THERMALLY CROWN SiO_2 FILM ELECTRET

In this paper,the influence of chemical surfaee modification on charge Storage stability in the thermally grown SiO_2 film electret is studied.A hydrophobic protective layer is formed on the surface of the SiO_2 film electret by an appropri- ate chemical surface modification(using HMDS or DCDMS).Generally,this hydrophobic layer prevents water absorption on the surface of SiO_2 and makes the SiO_2 electret an excellent electret.During the permanent charge captue and storage in the SiO_2 film electret,an electrochemical reaetion takes place and water is produced.The hydrophobic layer formed after chemical surface modification sometimes obstructs the excess water from diffusing out of the electret.In this condition,an unusual phenomenon occurs:the charges stored in the SiO_2 electret modified by HMDS or DCDMS decay faster than surface.