| 摘要 |
The electrodes of a semi-conductor device (see Division H1) are provided by depositing a <PICT:1104804/C6-C7/1> bi-metallic film, comprising a layer of molybdenum covered with a layer of gold or aluminium, over the surface of the device and etching to shape. The device may be of silicon covered with a layer of silicon oxide, the electrodes overlying the oxide except where they extend through windows and contact the silicon. The surface of the device is subjected to a series of cleaning steps and the metal layers are deposited using the apparatus shown in Fig. 3 in which the devices 25 are supported on a stainless steel sheet 24 heated by quartz infrared tubes 26 inside an evacuated bell jar 21. The molybdenum source comprises a molybdenum strip 29 the width of which is constricted at its centre so that when an electric current is passed through the strip the centre part is heated to just below its melting point and begins to evaporate. The source of the covering layer comprises a tungsten heating coil 27 arranged to evaporate a charge 28 of gold. A thin flash of aluminium may be deposited over the surface before the molybdenum and gold (or aluminium) layers. |
