Nanoscale Germanium Electronics

该提案是一项可行性研究，以确定在锗中制造纳米级电子器件的实用性，尺寸从几十纳米到原子尺度。数十亿磅的半导体工业是基于在硅晶片上制造的集成电路（IC），并且在过去的四十年中一直如此，其中每18个月将组件缩小两倍（摩尔定律）。然而，近年来，由于量子效应（例如隧穿），电路组件的小尺寸已经引入了许多麻烦的器件性能问题，并且将锗并入器件组件中被视为潜在的解决方案。在接近纳米尺度的器件中看到的上述量子效应的一个积极方面是，正在为未来几代IC和量子信息处理（QIP）应用探索明确利用量子力学的新器件范例。例如，有一些有趣的提议，用锗中的杂质或应变硅锗异质结构中的掺杂剂制造量子计算机。因此，它已成为至关重要的是要了解通过纳米级锗器件的电输运和锗中的单一和相互作用的掺杂剂的量子特性。为了提供制造锗纳米级掺杂剂器件的明确途径，将开发技术以（i）以原子精度将掺杂剂原子放置在锗晶体中的受控位置处，以便了解它们的基本性质，以及（ii）在锗中制造并电掩埋1原子厚的掺杂剂层（δ掺杂层）。该技术将利用扫描隧道显微镜（STM），它可以成像和操纵原子的物质，以图案化由氢原子制成的单原子厚的抗蚀剂层，用前体气体供应掺杂剂。然后，将使用相同的STM对制造的结构进行抛光。

This proposal is a feasibility study to determine the practicality of fabricating nanoscale electronic devices in germanium, of dimensions ranging from tens of nanometres to the atomic scale. The multi-billion pound semiconductor industry is based on integrated circuits (ICs) fabricated on silicon wafers and has been for the last forty years, with components being made smaller by a factor of two every eighteen months (Moore's Law). However, in recent years, the small size of circuit components has introduced a number of troublesome device performance issues due to quantum effects, such as tunnelling, and the incorporation of germanium into device components is seen as a potential solution. One positive aspect of the above mentioned quantum effects, seen in devices approaching nanoscale dimensions, is that new device paradigms which explicitly exploit quantum mechanics are being explored for future generations of ICs and for quantum information processing (QIP) applications. For example there are interesting proposals to make quantum computers from impurities in germanium or from dopants in strained Si-Ge heterostructures. Thus it has become crucial to understand the electrical transport through nanoscale germanium devices and the quantum properties of single and interacting dopants in germanium. In order to provide a clear pathway towards the fabrication of germanium nanoscale dopant devices, techniques will be developed to (i) place dopant atoms at controlled positions in a germanium crystal, with atomic precision, in order to learn about their fundamental properties and (ii) fabricate and electrically characterise buried 1-atom thick dopant layers (delta-doped layers) in germanium. The techniques will utilise a scanning tunnelling microscope (STM), which can image and manipulate matter atom-by-atom, to pattern a single atom thick resist layer made from hydrogen atoms, with a precursor gas supplying the dopants. The same STM will then be used to characterise the fabricated structures.