Integrated circuit resistor fabrication using focused ion beam
US5047827A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 20, 1990 |
| Grant date | Sep 10, 1991 |
| Priority date | — |
| Expiry date | Aug 20, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D84/209
Abstract
A high value, precision resistor (10) includes a doped region (18) having a boustrophedonic (folded or meandering) shape formed in a substrate (12). At least one section of the doped region (18) is formed by implantation using a focused ion beam. Where the entire doped region (18) is formed by the focused ion beam, the length thereof is selected to be large (10 to 100 times the width of the boustrophedonic shape) to maximize the accuracy of the resistor (10) by averaging over variations in grain size and implant dose. Alternatively, a probe resistor (32) and a plurality of similar unconnected doped sections (28) may be formed by means such as photolithography and flood ion implantation. The probe resistor (32) is measured at the desired operating temperature to determine the ratio of the measured resistance to the desired design resistance value. The unconnected doped sections (28) are then interconnected by plugs (40, 42, 44, 46), formed with a focussed ion beam, to program the fabricated resistor to exactly the designed resistance value at the desired operating temperature.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.