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一、引言GaAs器件和Si器件一样,也常常需要一种钝化膜来提高器件的可靠性,或是作为杂质选择扩散的掩膜。目前GaAs器件常用的介质膜有Si_3N_4膜、SiO_2膜、Al_2O_3膜和GaAs自身氧化膜(阳极氧化、等离子氧化等) 用正硅酸乙酯热分解生成SiO_2膜和PSG膜是硅平面工艺中常用的方法,这种方法工艺简单、安全、容易控制。但在GaAs衬底上如用Si器件的热分解工艺,当分解温度为700℃—800℃时,会使GaAs表面离解,造成缺陷,影响器件的电参数。为了防止GaAs衬底的分解,我们在尽可能低的温度下,预先在GaAs衬底上淀积一层薄膜,此膜可以
I. INTRODUCTION GaAs devices, like Si devices, often require a passivation film to increase the reliability of the device, or as a mask for selective diffusion of impurities. At present, the dielectric films commonly used in GaAs devices are Si 3 N 4 films, SiO 2 films, Al 2 O 3 films and GaAs self-oxide films (anodic oxidation, plasma oxidation, etc.), which are commonly used in the silicon planarization process by thermal decomposition of tetraethyl orthosilicate to form SiO 2 films and PSG films Method, this method is simple, safe, easy to control. However, the thermal decomposition process of Si devices on GaAs substrates, when the decomposition temperature is 700 ° C-800 ° C, dissociates the GaAs surface and causes defects, affecting the electrical parameters of the device. In order to prevent the decomposition of the GaAs substrate, we deposited a thin film on the GaAs substrate in advance at a temperature as low as possible,