中科院半导体材料科学重点实验室知识库

1.        设计并制作了一种新型的掺Fe掩埋异质结（BH）结构的InGaAsP-Si混合激光器，其III-V族部分采用三次MOCVD外延生长，对其相关的Zn掺杂浓度、Fe掺杂浓度、腐蚀条件以及外延参数等进行了详细研究。脉冲电流泵浦条件下，器件阈值电流约为100mA，阈值电流密度为11.9kA/cm²，单面最大输出功率为9mW，斜率效率约为0.04W/A，激射波长在1550nm附近，并实现了10 ℃的近室温连续工作。该技术提供了一种简单易行的厚片键合方案，避免了键合过程中器件破裂的问题，提高了键合成品率，同时，掩埋异质结可提供更好的侧向光场和载流子限制，改善了器件性能。

2.        设计并制作了一种新型的掩埋脊波导结构（BRS）的硅基混合激光器，通过不断优化相关工艺流程，成功实现了室温连续激射。器件阈值电流14mA，阈值电流密度1.55kA/cm²，单面最大输出功率为5.4mW，斜率效率为0.17W/A，激射波长在1562nm附近，特征温度T₀为50K。与掺Fe BH硅基混合激光器相比，只需两次外延，工艺简单，散热性能好，阈值电流低，出光功率大。

3.        设计并制作了一种基于III-V族分布反馈（DFB）结构的单波长硅基混合激光器，室温连续电流泵浦条件下，阈值电流5mA，单面最大输出功率1.5mW，激射波长在1536nm附近，边模抑制比（SMSR）为35dB，特征温度T₀约为33K，热阻为140℃/W。并在此基础上在III-V族有源区制作均匀的全息光栅，然后刻蚀不同的波导宽度，初步实现了8波长硅基混合激光器阵列。

4.        设计并制作了一种硅基分布反馈（DFB）结构的单波长硅基混合激光器，其DFB光栅制作在SOI表面的硅波导上，并且III-V族部分采用掩埋脊波导结构（BRS）的法布里-珀罗（FP）腔激光器。脉冲电流泵浦条件下，器件阈值电流约为50mA，阈值电流密度5.56 kA/cm²，斜率效率为0.006W/A，激射波长约为1546nm，边模抑制比（SMSR）为20dB。并在此基础上刻蚀不同的硅波导宽度，实现了4波长硅基混合激光器阵列。

Recent years, with the development of information technology, due to the influence of resistance-capacitance delay, limited bandwidth and high power dissipation, copper-based inter-connection cannot meet the requirements of large capacity data transmission. As the discrete components of Si photonics get mature, ever increasing attention has been paid to the Si based optical interconnect. However, due to its indirect band-gap, Si cannot achieve effective light emission, which is the major hurdle for optical interconnects. A practical way to achieve Si based laser will make optical interconnect possible. In the actual communication application, multiplexing technique is often used to improve the communication capacity. This dissertation mainly focuses on Si based light source used in optical interconnect, with SOI as the platform material, III-V compound as gain material, using low temperature selective area metal bonding (SAMB) method to achieve two kinds of Si based hybrid laser, with the advantages of  simple process and high yield. Following that, three kinds of multi-wavelength hybrid laser array is achieved, which makes much useful exploration for on-chip light source. The main results are outlined below:

1.        A Fe-doped buried heterostructure (BH) InGaAsP-Si hybrid laser is designed and fabricated, in which the III-V part needs three times MOCVD epitaxial growth, and the corresponding Zn, Fe doping concentration, corrosion condition and epitaxial parameters are discussed in detail. Under pulse current pumping condition, the threshold current is about 100mA, the threshold current density is 11.9kA/cm², the maximum single-facet output power is 9mW, the slope efficiency is about 0.04W/A, the lasing wavelength is about 1550nm, and the continuous-wave working temperature at 10°C is realized. The hybrid laser provides a simple thick wafer bonding technology, avoiding the device broken during bonging and improving the yield. Meanwhile, the BH provides better lateral carrier and optical field confinement to improve the device performance.

2.        A novel buried ridge waveguide structure (BRS) hybrid laser is designed and fabricated, and through continuous optimizing the fabrication process, the continuous-wave operation at room temperature is achieved. The threshold current is 14mA, the threshold current density is 1.55kA/cm², the maximum single-facet output power is 5.4mW, the slope efficiency is 0.17W/A, the lasing wavelength is about 1562nm, the characteristic temperature is 50K. Compared with Fe-doped BH hybrid laser, the BRS hybrid laser has the advantage of simple process of only twice epitaxial growth, good heat dissipation, low threshold current, and high output power. 

3.        A single wavelength hybrid laser with distributed feedback grating on III-V part is designed and fabricated. Under continous-wave pumping condition, the threshold current is 5mA, the maximum single-facet output power is 1.5mW, the lasing wavelength is about 1536nm, the side mode suppression ration (SMSR) is 35dB, the characteristic temperature is 33K, and the thermal resistance is 140℃/W. In the next step, through fabricating uniform holographic grating on the active region, and then etching the waveguide with different width, an eight-wavelength hybrid laser array is achieved.

4.        A single wavelength hybrid laser, with distributed feedback grating on Si waveguide and BRS Fabry-Perot cavity laser on III-V part, is designed and fabricated. Under pulse current pumping condition, the threshold current is about 50mA, the threshold current density is 5.56kA/cm², the slope efficiency is 0.006W/A, the lasing wavelength is about 1546nm, and the side mode suppression ration (SMSR) is about 20dB. In the next step, through etching the Si waveguide with different width, a four-wavelength hybrid laser array is achieved.

5.  A single wavelength hybrid laser, with distributed bragg reflector grating on Si waveguide and BRS Fabry-Perot cavity laser on III-V part, is designed and fabricated. Under continuous current pumping condition, the threshold current is about 20mA, the maximum single-facet output power is 42μW, the characteristic temperature is 32K, the lasing wavelength is about 1544nm, the side mode suppression ration (SMSR) is 24dB, and the thermal resistance is 72.8℃/W. In the next step, through etching the Si waveguide with different width, an eight-wavelength hybrid laser array is achieved. The above three multi-wavelength lasers are all based on holographic exposure and ordinary lithography technology, providing a simple process, low-cost multi-wavelength light source solution for WDM symtem.