Air gap forming method between integrated circuit (IC) interconnector and interlevel dielectric layer

Abstract

The invention discloses an air gap forming method between an integrated circuit (IC) interconnector and an interlevel dielectric layer. The air gap forming method comprises the steps of providing a semiconductor component, sequentially forming a first dielectric barrier layer and the interlevel dielectric layer on the semiconductor component, etching a sacrificial area on the interlevel dielectric layer, wherein the sacrificial area is exposed out of the first dielectric barrier layer, depositing oxide in the sacrificial area, etching a part of the oxide, forming a groove, continuously etching the oxide and the first dielectric barrier layer in the groove until source and drain regions or a grid electrode of the semiconductor component are exposed, forming a through hole, plating the interconnector inside the groove and the through hole in an electrochemical mode, eliminating the remaining oxide, and forming an air gap. According to the air gap forming method, the air gap is formed between the interconnector and the interlevel dielectric layer, and therefore a capacitance effect of the interconnector is reduced. Furthermore, resistance-capacitance (RC) delay of the interconnector is reduced, and signal transmission speed of the interconnector is accelerated.

Description

technical field [0001] The invention relates to semiconductor manufacturing technology, in particular to a method for forming an air gap (air gap) between an IC interconnection (interconnection) and an interlayer dielectric layer (ILD, interlayerdielectric). Background technique [0002] As the size of IC (Integrated Circuit, integrated circuit) becomes smaller and smaller, the RC delay generated between metal lines such as interconnection (interconnection) gradually replaces the delay of the transistor itself and becomes the main factor limiting the operating speed of the IC. . The speed of signal transmission in the circuit is affected by the product of resistance R and capacitance C. The larger the RC product, the slower the speed and the higher the delay. Conversely, the smaller the RC product, the faster the signal transmission speed and the delay lower. For an interconnection (such as a copper interconnection), its resistance R is determined by its own material prope...

AI Technical Summary

Problems solved by technology

Due to the existence of this structure, the interconnection 14 will be affected by the RC delay during signal transmission, thus limiting the operating speed of the IC

Images