Resistor structure and its forming method

Abstract

The invention discloses a resistor structure and method for forming the same. The resistor structure for an integrated circuit includes a first set of contacts connected between a semiconductor layer and a first conductive layer; a second set of plugs connected between the first conductive layer and a second conductive layer, wherein the first set of contacts and the second set of plugs are coupled together as a first resistor segment to provide a predetermined resistance for the integrated circuit; a third set of contacts connected between the semiconductor layer and the first conductive layer; a fourth set of plugs connected between the first conductive layer and the second conductive layer; wherein the contacts of the third set are coupled with the plugs of the fourth set as a second resistor segment adjacent to the first resistor; and a conductive graph serially connected to the first and the second resistors.

Description

technical field

[0001] The present invention relates to integrated circuit design, and in particular to a stacked resistor structure suitable for use in integrated circuits. Background technique

[0002] An integrated circuit often contains many resistors. For example, an analog-to-digital converter (ADC) may include groups of resistors to divide the voltage. Ideally, the resistance values ​​of these resistor groups should be matched to divide the voltage equally. Traditionally, the above-mentioned resistors are manufactured by forming some silicide or non-silicide polysilicon layers on a silicon wafer; the above-mentioned resistors can also be manufactured by forming N-type or P-type doped regions on the semiconductor substrate of the wafer. device.

[0003] One of the disadvantages of the conventional resistors described above is that they require a large surface area. For example, for a reference voltage resistor-ladder used in an 8-bit analog-to-digital converter, th...

Images