Method of fabricating semiconductor structure

Abstract

A method of fabricating a semiconductor structure is disclosed, in which a pad above a connecting section and metal structures above a functional section are formed from the same metal layer. This design enables the simultaneous formation of the pad and the metal structures by forming a single metal layer and performing thereon a selective etching process, thereby leading to the advantages of process simplification, throughput improvement and cost reduction.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS[0001]This application claims the priority of Chinese patent application number 201410243358.7, filed on Jun. 3, 2014, the entire contents of which are incorporated herein by reference.TECHNICAL FIELD[0002]The present invention relates generally to semiconductor device fabrication, and in particular, to a method of fabricating a semiconductor structure.BACKGROUND[0003]With the development of multimedia technology, digital still cameras, digital video cameras and mobile phones with camera functions have gained increasing popularity among consumers. In addition to their pursuit for the miniaturization of these devices, customers are also demanding for an increasing improvement in the quality (i.e., clarity) of images captured by such devices. On the other hand, whether such a device could capture a high imaging quality heavily depends on what components the device incorporates. In particular, the imaging quality of a camera is determined by an i...

AI Technical Summary

Benefits of technology

[0007]It is therefore an objective of the present invention to provide a method of fabricating a semiconductor structure, which is capable of simplifying semiconductor device fabrication processes (e.g., fabrication processes of CMOS sensors), improving production throughput, reducing production cost, and enhancing light absorption efficiency.

[0022]As described above, the method of the present invention provides the following advantages over the conventional methods.

[0023]Firstly, as the pad is connected to the connecting layer by the conductive structure and the pad and the metal structure are formed from the same metal layer, the advantages of process simplification, throughput improvement and cost reduction can be achieved by simultaneously fabricating the pad and the metal structure through forming a single metal layer and performing thereon a selective etching process.

[0024]Secondly, the only element disposed between the metal structure and the substrate is the protective insulating layer, which is particular beneficial for the applications where the metal structure is implemented as one or more light-blocking layers for optical filters disposed between the light-blocking layers, because this makes the protective insulating layer the only element disposed between the optical filters and the substrate and thus enables paths between the optical filters and corresponding photodiodes to be only intervened by the protective insulating layer but no protective layer for the pad, thereby enhancing light absorption efficiency of the CMOS sensor.

Problems solved by technology

However, as the light-blocking layers and the pad are conventionally formed in different processes using different techniques, the sensor fabrication process is associated with high complexity and cost and suffers from a low throughput.

Another deficiency of the conventional CMOS sensor is that a protection layer for the pad, which causes reduction of light absorption, intervenes between the optical filters and the photodiodes.

Images