We present a method to fabricate tensile-strained germanium-on-insulator (GOI) substrates using heteroepitaxy and layer transfer techniques. The motivation is to obtain a high-quality wafer-scale GOI platform suitable for silicon-compatible optoelectronic device fabrication. Crystal quality is assessed using X-Ray Diffraction (XRD) and Transmission Electron Microscopy. A biaxial tensile film strain of 0.16% is verified by XRD. Suitability for device manufacturing is demonstrated through fabrication and characterization of metal-semiconductor-metal photodetectors that exhibit photoresponse beyond 1.55 {\mu}m. The substrate fabrication process is compatible with complementary metal-oxide-semiconductor manufacturing and represents a potential route to wafer-scale integration of silicon-compatible optoelectronics.

Tensile-Strained Germanium-on-Insulator Substrate Fabrication for Silicon-Compatible Optoelectronics

Electronic properties and defect levels induced by <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="d1e1065" altimg="si112.svg"><mml:mrow><mml:mi>n</mml:mi><mml:mo>/</mml:mo><mml:mi>p</mml:mi></mml:mrow></mml:math>-type defect-complexes in Ge

We investigate the effect of the annealing temperature and annealing time on the bubble evolution on the hydrogen ion (H+)-implanted germanium (Ge) substrate. It is found that the H2 aggregates gradually with the increase of the annealing time, and the aggregation rate of the H2 increases with the increase of the annealing temperature. Low-temperature Ge/Si wafer bonding (a-Ge interlayer) and Smart-Cut™ technique are applied to fabricate high-quality Ge-on-insulator (GOI). It is proved that thick Ge film is more difficult to be exfoliated from the Ge substrate. As long as the pressure in the bubbles is high enough, although the bubbles do not burst on the Ge surface, the lateral diffusion of H2 may occur to trigger the exfoliation of the Ge film. The contact of the wafers leads to the lateral merging of the small bubbles, resulting in the increase of the bubble size at the edge of the big void. It is believed that high bonding strength between Ge and SiO2 is essential to resist the high pressure in the bubble for the successful exfoliation of the Ge film. The point defects in the Ge film can be totally eliminated either by high-temperature annealing or by nanosecond pulse laser annealing, resulting in the improvement of the Ge film quality.

https://iopscience.iop.org/article/10.1088/1361-6641/ab6bb5/pdf

Xuewen Ou

Papers

Bubble evolution mechanism and defect repair during the fabrication of high-quality germanium on insulator substrate