| 摘要 |
1,202,280. Resistors. INTERNATIONAL BUSINESS MACHINES CORP. 7 Nov., 1967 [29 Dec., 1966], No. 50488/67. Heading H1S. [Also in Divisions C7 and G1] The maximum surface temperature attained by an article during a manufacturing process is measured by means of a resistor of which the resistance and temperature coefficient of resistance are changed permanently in dependence upon the maximum temperature to which the resistor is subjected, but independent of the length of time for which it is subjected to that temperature, which may therefore be determined by subsequent measurements of resistance or temperature coefficient of resistance of the resistor. A maximum surface temperature device 10, Fig. 3, comprises a silicon or molybdenum substrate 12, an insulating silicon dioxide layer 13, a thin film resistor 14 of a mixture of specified proportions of chromium and silicon monoxide, conductive layers 15, 16 and lead wires 18. A protective coating 17 shields the film from reactive gases. In use, the device measures the maximum surface temperature attained by a semi-conductor wafer (50), Figs. 4, 5, 6 (not shown), which is heated in an R.F. sputtering apparatus (see Heading C7A), a layer of gallium or a gallium indiumalloy being interposed between the substrate and the wafer to provide good thermal contact. Fig. 7 shows that the residual resistance of each of four similar devices, having a resistor film of 80 atomic per cent chromium and 20 atomic per cent silicon monoxide, was 63% of the initial resistance, for a maximum temperature of 500‹ C., the time taken to reach that temperature being different in each case. Fig. 8 illustrates the variation of residual resistance as a function of atomic percentage content of silicon monoxide with maximum temperature as a parameter. Fig. 9 illustrates the abrupt changes in three temperature coefficient of resistance characteristics, the temperature in brackets being the actual temperature maximum in each case, while that without refers to the point of change on the characteristic in each case. Figs. 1 and 2 (not shown) illustrate another embodiment of the device in which the substrate (11) is of silicon there being no protective coating on the resistive film. |
