Selective-area metal-organic vapor phase epitaxy for monolithically-integrated semiconductor photonic circuits

1.椭圆偏振光谱在线监测金属-有机气相外延(MOVPE)我们尝试了用椭圆偏振光谱对金属-有机气相外延(MOVPE)进行在线监测，并展示了其观察生长表面状态的能力。应用观察结果，我们制作了具有1~3个分子层的InGaAs/InP量子阱，并用CTR方法对其进行了表征。从CTR表征的信号被发现优于以往的任何报道，从而我们证实了他们的界面是真正的单层突变。生长速率和薄膜质量的纵向分析及其在生长条件优化中的应用我们通过制备一种特殊的衬底，实验研究了InP和GaAsMOVPE中沿先驱体流动方向生长速率和薄膜质量的纵向分布，并与我们新开发的生长模拟软件进行了比较。在此基础上，我们确定了高温下表面粗糙度的形成机理--…合理地确定了生长条件，避免了表面粗糙度。作为单片光子集成电路的主/被动集成技术，我们提出并发展了金属-有机气相扩散增强型选区外延(MOVE)。利用这一技术，我们在体相材料中实现了1.55微米的有源区和被动区之间的带隙差(由于成分变化)，在量子阱中(由于成分和厚度的变化)实现了高达200 nm的带隙差。这些数字远远大于传统的数字。选择性区域MOVPE的模拟为了统一理解MOVPE中的选择性区域生长，我们开发了一个通用的模拟程序。利用能独立考虑侧向水汽扩散和侧向表面迁移影响的二维模型，成功地解释了实验结果。结果表明，在常规的选择性区域生长中，表面迁移通道占主导地位，而在迁移过程中，侧向蒸汽扩散通道占主导地位。首次用MOVE制造光子器件和集成电路MOVE是世界上唯一能够形成波导阵列阵的选区生长技术。利用这一特性，我们首次成功地用选区外延技术制作了1×2 MMI耦合器。此外，利用主动/被动集成能力，首次制作了一种用于光开关的光放大门开关电路，并对其工作性能进行了验证。较少

1. In-situ monitoring of MOVPE by spectroscopic ellipsometryWe here tried in-situ monitoring of metal-organic vapor phase epitaxy (MOVPE) by spectroscopic ellipsometry, and showed its ability to observe growth surface state. Applying the results of the observation, we made InGaAs/InP quantum wells having 1 to 3 molecular layers, and characterized them using CTR method. The signals from the CTR characterization were found to be superior to any previous reports, thereby we confirmed that their interfaces were truly monolayer abrupt.2. Longitudinal analysis of growth rate and film quality and Its application to growth condition optimizationWe experimentally investigated longitudinal distribution of growth rate and film quality along the direction of precursor flow in InP and GaAs MOVPE by preparing a special susceptor, and compared the results with our newly developed growth simulator. Based on the results, we specified the mechanism of surface roughness formation at high temperatures, an … More d made logical determination of growth conditions for avoiding the surface roughness possible.3. Development of metal-organic vapor-phase-diffusion-enhanced selective-area epitaxyAs an active/passive integration technology in monolithic photonic integrated circuits, we proposed and developed metal-organic vapor-phase-diffusion-enhanced selective-area epitaxy (MOVE). By utilizing this technique, we could achieve band gap difference between active and passive regions at 1.55mum as large as 200nm in bulk material (due to composition variation), and as large as 500nm in quantum wells (due to composition and thickness variation). These numbers are by far larger than conventional ones.4. Simulation of selective-area MOVPEFor the purpose of understanding selective-area growth in MOVPE in a unified manner, we developed a universal simulator. By utilizing a two dimensional model that could take the effects of lateral vapor diffusion and lateral surface migration independently into account, we could explain the experimental results successfully. It was shown that, in the conventional selective-area growth, the surface migration channel was dominant whereas, in the MOVE, the lateral vapor diffusion channel was dominant.5. First fabrication of photonic devices and integrated circuits by MOVEThe MOVE is the only selective-area growth technology in the world which is able to form waveguide arrays. By applying this feature, we succeeded in fabricating 1x2 MMI couplers by selective-area epitaxy for the first time. Furthermore, by utilizing active/passive integration capability, we fabricated an optical amplifier gate switch circuit for photonic switching for the first time, and confirmed its operation. Less