Controlled Spalling of 4H Silicon Carbide with Investigated Spin Coherence for Quantum Engineering Integration

Area of Science:

• Materials Science
• Semiconductor Physics
• Quantum Information Science

Background:

• 4H silicon carbide (4H-SiC) possesses properties ideal for power electronics and quantum technologies.
• High cost of 4H-SiC substrates necessitates efficient film transfer and substrate reuse methods.
• Atomic defect qubits in 4H-SiC are promising for quantum computing and networking.

Purpose of the Study:

• To develop and demonstrate controlled spalling and layer transfer of single crystal 4H-SiC.
• To enable the reuse of expensive 4H-SiC substrates.
• To assess the quality of spalled 4H-SiC films for quantum applications.

Main Methods:

• Utilized advanced stressor layer thickness control for spalling.
• Implemented refined spalling crack initiation techniques.
• Performed coherent spin control experiments on divacancy qubits in spalled films.

Main Results:

• Successfully demonstrated controlled spalling of 4H-SiC, a crystal with high fracture toughness.
• Achieved coherent spin control of neutral divacancy (VV0) qubit ensembles in spalled 4H-SiC films.
• Measured a quasi-bulk spin coherence time (T2) of 79.7 μs in the transferred films.

Conclusions:

• Controlled spalling is a viable technique for transferring high-quality 4H-SiC films.
• Spalled 4H-SiC films maintain excellent properties for quantum qubit applications.
• This method facilitates substrate reuse, reducing costs for advanced semiconductor applications.