Development of 3D P in Si quantum computing architecture for error correction

Phosphorus donor devices in silicon fabricated using STM hydrogen resist lithography are typically fabricated in a 2D design using a single lithographic layer. However in order to achieve quantum error correction with a surface code architecture we need to be able to fabricate devices in three dimensions using multiple lithographic layers [1]. Here I will present on the fabrication challenges associated with transitioning from single layer devices to a multilayer structure and the techniques we used to overcome these challenges, allowing for the fabrication of high quality multilayer devices. I will also present electrical measurements from initial three layer vertical SET devices, the smallest element of the proposed surface code architecture [1], in which the SET source, island and drain are all separated vertically across three lithographic layers.

1. Hill et al, Science Advances, 1, 9, e1500707 (2015)