| 摘要 |
In accordance with the teachings of this invention, resistors are fabricated in semiconductor devices utilizing a layer of semiconductor material having a preselected resistivity. Means are provided for electrically isolating the semiconductor region from the regions located beneath, and isolation to adjacent regions is provided by forming a groove. Resistance value of a particular resistor fabricated in accordance with the teachings of this invention is dependent, in a coarse fashion, on the length and width of the resistor, as well as the resistivity of the semiconductor material used to fabricate the resistor. However, the final resistance value is determined by the diffusion of high concentration isolation dopants which serve to accurately control the effective cross-sectional area of the resistor. Once the rough physical dimensions of a resistor have been established, its actual resistance value is controlled very closely by, for example, introducing isolation dopants, diffusing the isolation dopants for a specified period of time, measuring a resistance value and, if necessary, further diffusing the isolation dopants. This iterative process of diffusing isolation dopants and measuring resistance value is repeated as required in order to fabricate resistors of desired resistance values.
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