A detailed and didactic analysis of the diffusivity in a 2D inversion layer is carried out, providing its dependence on carrier density and temperature. Then, a comprehensive study of the diffusion and drift current components in a MOSFET is proposed. Their dependence with gate and drain voltages is investigated down to deep cryogenic temperature, revealing that at T = 4 K the diffusion current is nearly constant in strong inversion whatever the mobility law. Finally, based on our diffusivity analysis, a new formulation of the diffusion noise valid from weak to strong inversion down to very low temperature has been developed.

中文翻译：

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在低至深低温下工作的MOSFET中的扩散电流

对二维反型层中的扩散率进行了详细的教学分析，确定其对载流子密度和温度的依赖性。然后，提出了对MOSFET中扩散和漂移电流分量的综合研究。研究了它们在深低温下对栅极和漏极电压的依赖性，发现无论迁移率定律如何，在T = 4 K时，扩散电流在强反转中几乎恒定。最后，根据我们的扩散率分析，开发了一种新的扩散噪声公式，可以有效地实现从弱到强反演到非常低的温度。