Award

The overall objective of this program is to explore the possibility of extending the PinSi dopant placement technology known as Atomically Precise Advanced Manufacturing APAM beyond donor dopants and combine ptype and ntype dopants in the same device. APAM technology allows us to reach much higher dopant densities in 2D than possible in 3D, and with the atomic precision placement, to create much smaller base dimensions in Bipolar Junction Transistors BJTs. As a result, devices such as the Tunneling Bipolar Junction Transistor and the Esaki Transistor become feasible in a siliconbased technology. We believe that analog rather than digital circuits will be best served by these devices. In the initial Phase I program, we chose a preferred acceptor dopant precursor, BCl3, and have demonstrated the ability to create patterned structures of B, and of both B and P in the same device, with the patches of dopants aligned to each other with atomic precision. The alignment process has benefited from the ability to quickly relocate the device area, and identify the location of incorporated dopants, capabilities developed in our parallel Phase I STTR DESC0020827 project. During Phase II, we will optimize the fabrication processes, especially the immature B incorporation process, and will use this to first create pn junction devices, and later pnp and npn devices such as Bipolar Junction Transistors, and explore their characteristics and performance. We will focus on device parameters, such as depletion width and builtin potential, that are likely to yield devices with useful characteristics of commercial interest to our large semiconducting industry partners. The expected very small bases should make possible extremely highfrequency devices. Based on experimental data from buried deltalayers of dopants, published literature on scaled BJTs and our ability to pattern them with atomic resolution, we see an opportunity to create a new class of BJTs with significantly improved gainbandwidth product, lownoise operation, unprecedented control of device performance for extremely wellmatched differential pairs, cryogenic operation, and being only one atom thick a high level of Rad Hardness. If we are successful in creating breakthrough performance improvements in these areas these devices they should be useful for the following applications: Defense, Space, Quantum computer backplane electronics for control and error correction of qubits, Ultrasensitive sensors.