Trimming of silicon-on-insulator devices via localised laser annealing (Conference Presentation)
Trimming of silicon-on-insulator devices via localised laser annealing (Conference Presentation)
复制标题
通过局部激光退火对绝缘体上硅器件进行修整（会议演示）
DOI：
10.1117/12.2507212
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Biryukova V
中科院分区：
文献类型：
--
作者：
Biryukova V
绝缘体上硅器件对制造误差特别敏感。作为示例，波导高度或宽度的小至1 nm的偏差直接转化为使用所述波导构造的任何干涉测量装置（诸如环形谐振器）的传递函数的1 nm偏移。因此，即使制造公差不断提高，制造后处理往往是确保器件均匀性的唯一方法，特别是要求苛刻的应用。提出了一种基于HSQ包覆层局部激光退火的SOI器件制造后修整新方法。HSQ是一种多用途材料，由于其与传统二氧化硅的相似性，通常用于SOI器件的制造中，既作为电子束光刻抗蚀剂的掩模材料，又作为包覆层或平面化层。然而，与二氧化硅不同的是，HSQ的折射率可以通过热处理显著改变（高达ΔnHSQ = 3.26*10-2）。我们利用这一特性进行修整，通过用HSQ层包覆针对TE传播优化的常规SOI波导（高度h=220 nm，宽度= 500 nm），然后通过激光退火永久地改变包覆层的折射率。这种方法允许我们选择单个设备，并仅在必要时应用更改。作为演示，我们修剪了1.3nm的跑道谐振器的谐振。该技术已被证明是稳健的，在微调后7天没有观察到参数漂移，并且没有与相邻器件的热串扰。此外，与其前身不同，它基于标准制造工艺，不需要昂贵的专业设备。
Silicon-on-Insulator devices are particularly sensitive to fabrication errors. As an example, a deviation in waveguide height or width of as little as 1nm translates directly to a 1nm offset in the transfer function of any interferometric devices (such as a ring resonator) constructed using the said waveguide. Therefore, even as fabrication tolerance continues to improve, post-fabrication treatment is often the only way of ensuring device uniformity for particularly demanding applications. This work proposes a novel approach for post fabrication trimming of SOI devices based on localised laser annealing of HSQ cladding layer. HSQ is a versatile material often used in fabrication of SOI devices as both the mask material for electron-beam lithography resist and as a cladding or planarization layer due to its similarity to conventional silica. However, unlike silica, the refractive index of HSQ can be changed significantly (up to ΔnHSQ = 3.26*10-2) by thermal processing. We utilise this property for trimming by cladding a conventional SOI waveguide optimised for TE propagation (height h=220 nm, width=500nm) with a layer of HSQ and then permanently changing the refractive index of the cladding via laser annealing. This approach allows us to select individual devices and only apply the change where necessary. As a demonstrator, we trim a resonance of a racetrack resonator by 1.3nm. The technique has proven to be robust with no parameter drift observed 7 days after trimming and no thermal cross-talk to neighbouring devices. Furthermore, unlike its predecessors, it is based on a standard fabrication process and does not require expensive specialised equipment.