The development of semi-insulating silicon substrates for microwave devices

Conference item

The concept of fully encapsulated, semi-insulating silicon (SI-Si) Cz-SOI substrates for silicon microwave devices is presented. Results show that, using gold as a compensating impurity, a silicon resistivity of 180kΩcm can be achieved. Sufficiently high resistivity substrates for microwave applications are obtained by depositing gold on silicon and annealing for one hour at 1000°C. Silicon oxide and silicon nitride are considered as diffusion barriers for use in the new technology. At 1000°C the diffusivity of gold in PECVD silicon nitride is found to be ∼3.7×10-13cm 2s-1, whilst for silicon oxide it is less than 6×10-14cm2s-1. These results imply that silicon nitride would be ineffective as a diffusion barrier in the SI-Si technology but that a silicon oxide BOX 600nm thick might allow devices to be processed with a thermal budget of up to 15 hours at 1000°C without impurity contamination. © The Electrochemical Society.

Authors: Jordan, D; Haslam, R; Mallik, K; Wilshaw, P

• Host title: ECS Transactions
• Volume: 16
• Issue: 6
• Pages: 41-56
• Publication date: 2008-01-01
• DOI: 10.1149/1.2980291
• EISSN: 1938-6737
• ISSN: 1938-5862
• ISBN: 9781566776523