Abstract It is increasingly important to reduce the cycle time of epitaxial growth, in order to reduce the costs of device fabrication, especially for GaN based structures which typically have growth cycles of several hours. We have performed a comprehensive study using metal-organic vapor phase epitaxy (MOVPE) investigating the effects of changing GaN growth rates from 0.9 to 14.5 µm/h. Although there is no significant effect on the strain incorporated in the layers, we have seen changes in the surface morphology which can be related to the change in dislocation behaviour and surface diffusion effects. At the small scale, as seen by AFM, increased dislocation density for higher growth rates leads to increased pinning of growth terraces, resulting in more closely spaced terraces. At a larger scale of hundreds of µm observed by optical profiling, we have related the formation of grains to the rate of surface diffusion of adatoms using a random walk model, implying diffusion distances from 30 µm for the highest growth rates up to 100 µm for the lowest. The increased growth rate also increases the intrinsic carbon incorporation which can increase the breakdown voltage of GaN films. Despite an increased threading dislocation density, these very high growth rates of 14.5 µm/hr by MOVPE have been shown to be appealing for reducing epitaxial growth cycle times and therefore costs in High Electron Mobility Transistor (HEMT) structures.

中文翻译：

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通过用于高电子迁移率晶体管的金属有机气相外延在 200mm 硅上实现高生长率 GaN

摘要 为了降低器件制造成本，减少外延生长的周期时间变得越来越重要，特别是对于生长周期通常为几个小时的基于 GaN 的结构。我们使用金属有机气相外延 (MOVPE) 进行了一项综合研究，调查了 GaN 生长速率从 0.9 到 14.5 µm/h 变化的影响。虽然对层中的应变没有显着影响，但我们已经看到表面形态的变化，这可能与位错行为和表面扩散效应的变化有关。在小尺度上，如 AFM 所见，更高的生长速率增加的位错密度导致生长阶地的钉扎增加，导致阶地间隔更近。在通过光学剖面观察到的数百微米的更大尺度上，我们使用随机游走模型将晶粒的形成与吸附原子的表面扩散速率联系起来，这意味着扩散距离从 30 µm（最高生长速率）到 100 µm（最低生长速率）。增加的生长速率也增加了本征碳的结合，这可以增加 GaN 薄膜的击穿电压。尽管增加了穿透位错密度，但 MOVPE 的这些 14.5 µm/hr 的非常高的增长率已被证明对减少外延生长周期时间和高电子迁移率晶体管 (HEMT) 结构的成本具有吸引力。增加的生长速率也增加了本征碳的结合，这可以增加 GaN 薄膜的击穿电压。尽管增加了穿透位错密度，但 MOVPE 的这些 14.5 µm/hr 的非常高的增长率已被证明对减少外延生长周期时间和高电子迁移率晶体管 (HEMT) 结构的成本具有吸引力。增加的生长速率也增加了本征碳的结合，这可以增加 GaN 薄膜的击穿电压。尽管增加了穿透位错密度，但 MOVPE 的这些 14.5 µm/hr 的非常高的增长率已被证明对减少外延生长周期时间和高电子迁移率晶体管 (HEMT) 结构的成本具有吸引力。