In order to test whether field emission from tetrahedrally bonded amorphous (ta-C) is affected by the back contact material we have carried out a series of emission experiments on Filtered Cathodic Vacuum Arc (FCVA) produced ta-C films. The measurements were made on identical films of approximately 25 nm thickness which have been grown simultaneously on various substrates of different work function. For these experiments the substrates used were p-type c-Si, n-type c-Si, SnO_2, tungsten, gold, lead, aluminium, molybdenum, chromium and titanium. Threshold fields for emission were generally in the range of 5 -15 V/micron and showed no direct dependence on back contact material work function. Films grown on Ti and W however had much higher threshold fields in the range 30-35 V/micron and this is thought to be associated with the native oxide which was present between the back contact and the ta-C film. As grown ta-C is also known tohave a 1-2 nm thick sp~2 rich layer on its surface and this layer may also have some effect on field emission. The layer was etched in either an O_2 or H_2 plasma and both etched surfaces led to improved emission efficiency.
展开▼
机译：为了测试四面键合的非晶态（ta-C）的场发射是否受到背接触材料的影响，我们对过滤阴极真空电弧（FCVA）生产的ta-C膜进行了一系列发射实验。在大约25 nm厚的相同膜上进行测量，这些膜同时在具有不同功函数的各种基板上生长。对于这些实验，所用的衬底是p型c-Si，n型c-Si，SnO_2，钨，金，铅，铝，钼，铬和钛。发射的阈值场通常在5 -15 V /微米的范围内，并且没有直接依赖于背接触材料的功函数。然而，在Ti和W上生长的薄膜具有更高的阈值场，范围在30-35 V /微米之间，这被认为与背面接触和ta-C薄膜之间存在的天然氧化物有关。众所周知，生长的ta-C在其表面上具有1-2 nm厚的sp〜2富集层，并且该层也可能对场发射产生某些影响。该层在O_2或H_2等离子体中被蚀刻，并且两个蚀刻表面均导致发射效率的提高。
展开▼
