KR19980046320A - Semiconductor device manufacturing method - Google Patents

Abstract

The metal to be embedded in the contact hole of the semiconductor device is formed before the contact hole is formed, thereby eliminating the process of embedding the metal layer in the contact hole. As a result, the semiconductor device manufacturing method can simplify the process and increase productivity by reducing energy during the exposure process for forming contact holes.

Description

Semiconductor device manufacturing method

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a semiconductor device, in particular, a method of manufacturing a semiconductor device which can simplify a process and increase productivity by forming a metal to be filled in a contact hole before the contact hole is formed.

In general, a metal layer is formed in a double or multiple layers in a semiconductor device manufacturing process, and an intermetallic insulating layer is formed between the metal layers for insulation and planarization. In addition, the connection between the metal layers is made through contact holes formed in the interlayer insulating film. A method of forming a contact hole of a conventional semiconductor device will be described with reference to FIGS. 1A and 1E as follows.

FIG. 1A is a cross-sectional view of the oxide film 4 being formed on the entire upper surface after the field oxide film 2 and the gate electrode 3 are sequentially formed on the silicon substrate 1.

FIG. 1B is a cross-sectional view of the photosensitive film 5 and the mask 6 formed to grind the oxide film 4 by a chemical mechanical polishing method and then form contact holes.

FIG. 1C is a cross-sectional view of the contact hole A formed by performing an etching process using the photosensitive film 5.

FIG. 1D is a cross-sectional view of the barrier metal layer 7 and the metal layer 8 embedded in the entire upper surface after removing the patterned photosensitive film 5.

FIG. 1E is a cross-sectional view of the metal layer 7 flattened by an etchback process or a chemical mechanical polishing method.

As described above, the conventional method of forming a contact hole is, firstly, productivity is lower than that of the photo process due to the large exposure energy in the contact hole mask process, and secondly, the aspect ratio increases as the size of the contact hole decreases. When the contact hole is filled with metal, there is a problem in that a process having good step coverage must be used.

Accordingly, an object of the present invention is to provide a method of manufacturing a semiconductor device capable of solving the above problems by forming a metal to be filled in the contact hole before the contact hole is formed.

The present invention for achieving the above object is a step of sequentially forming a field oxide film and a gate electrode on the silicon substrate on which the junction region is formed, sequentially forming a barrier metal layer and a metal layer on the entire upper surface, and polishing the metal layer to planarize Forming a metal layer pattern and a barrier metal layer pattern connected to the junction region by patterning the metal layer and the barrier metal layer, and forming an oxide film on the entire upper surface of a silicon substrate, and then exposing the metal layer pattern to expose the metal layer pattern. It is characterized by consisting of a step of polishing.

1A to 1E are cross-sectional views illustrating a method for forming a contact hole in a conventional semiconductor device.

2A to 2D are cross-sectional views illustrating a method of manufacturing a semiconductor device in accordance with the present invention.

Explanation of symbols on the main parts of the drawings

1 and 11: silicon substrate 2 and 12: field oxide film

3 and 13: gate electrode 4 and 18: oxide film

5 and 16: photosensitive film 6 and 17: mask

7 and 14: barrier metal layer 8 and 15: metal layer

Hereinafter, with reference to the accompanying drawings will be described in detail the present invention.

2A to 2D are cross-sectional views illustrating a method of manufacturing a semiconductor device in accordance with the present invention.

FIG. 2A is a cross-sectional view of the barrier metal layer 14 and the metal layer 15 formed on the entire upper surface after the gate electrode 13 is formed on the silicon substrate 11.

FIG. 2B is a cross-sectional view of the photosensitive film 16 and the mask 17 formed on the entire upper surface after polishing by the chemical mechanical polishing method to remove the step of the metal layer 15. At this time, the photosensitive film 16 uses either a negative photosensitive film or a positive photosensitive film.

As illustrated in FIG. 2C, the photosensitive layer 16 is patterned using the mask 17, and then the exposed metal layer 15 and the barrier metal layer 14 are etched to form a metal layer pattern 15A and a barrier metal layer pattern ( 14A). The barrier metal layer pattern 14A is connected to the junction region (not shown).

As shown in FIG. 2D, after the photosensitive film 16 is removed, an oxide film 18 is formed on the entire upper surface, and the oxide film is polished to expose the metal layer pattern 15A by chemical mechanical polishing.

As described above, the metal to be embedded in the contact hole is formed before the contact hole is formed, thereby eliminating the process of embedding the metal layer in the contact hole. As a result, the process is simplified and the exposure energy can be reduced to increase productivity.

Claims (4)

Sequentially forming a field oxide film and a gate electrode on the silicon substrate on which the junction region is formed, and sequentially forming a barrier metal layer and a metal layer on the entire upper surface thereof; Grinding and planarizing the metal layer; Patterning the metal layer and the barrier metal layer to form a metal layer pattern and a barrier metal layer pattern connected to the junction region; And forming an oxide film on the entire upper surface of the silicon substrate, and polishing the oxide film to expose the metal layer pattern. The method of claim 1, wherein the polishing of the metal layer is performed by a chemical mechanical polishing method. The method of claim 1, wherein the photosensitive film is one of a positive photosensitive film and a negative photosensitive film. The method of claim 1, wherein the polishing of the oxide film is performed by a chemical mechanical polishing method.