Semiconductor device and manufacturing method thereof

Abstract

In manufacturing a semiconductor device, the first gettering layer is formed on the backside of a wafer, and the second gettering layers are then formed on the backside and side surfaces of a chip, allowing these gettering layers to serve as trapping sites against metallic contamination that generated after backside grinding in assembly processes.

Description

[0001] This application claims priority to prior application JP 2004-88308, the disclosure of which is incorporated herein by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to a semiconductor device and a manufacturing method thereof and, particularly, to a semiconductor device and a manufacturing method thereof which can prevent characteristic deterioration due to metallic contamination which occurs in a backside grinding process and a package assembly process performed after formation of desired devices, wiring, and insulating film on a main surface of a semiconductor substrate. [0004] 2. Description of the Related Art [0005] A conventional semiconductor device is fabricated as follows, in accordance with a process flowchart shown in FIG. 1, electronic devices 3, wiring 4, an interlayer Insulating film 5, and the like, are formed on a surface of a silicon substrate 1. Thereafter a substrate's backside 6 is grinded so th...

AI Technical Summary

Benefits of technology

[0012] An object of the present invention is to resolve these problems and provide a semiconductor device and a manufacturing method thereof which can prevent characteristic deterioration due to metallic contamination which occurs during backside grinding, dicing and package assembly.

[0013] In the present invention, a thermal treatment is applied to a backside grinding damage layer or a dicing damage layer in an atmosphere containing an impurity, thus forming a gettering layer to capture a contaminating metal. Furthermore, by using a material containing less contaminating metal and cleaning a contaminating metal away, concentration of the contaminating metal is reduced, thus obtaining a semiconductor device manufacturing method and a semiconductor device which can prevent characteristic deterioration due to metallic contamination which occurs in backside grinding and package assembly.

Problems solved by technology

Moreover, in the subsequent dicing process, dicing damages, which are similar to grinding damages, are introduced into the side surfaces of chips and metallic contamination is also introduced into the side surfaces of the chips.

As described above, once a contaminating metal reaches an electronic device on a main surface of a substrate, various problems become apparent.

For example, when a contaminating metal reaches the depletion layer of a source / drain junction, it leads to the formation of surface state and thus causes the generation of Junction leakage current.

Furthermore, if a contaminating metal reaches a gate insulating film, insulating film leakage current increases.

Because of such increases in the leakage current, characteristics of an electronic device are deteriorated.

The above-mentioned problem has been increasingly serious particularly in recent years as a multi-chip package, wherein chips with a reduced thickness of about 100 μm are stacked, has been commercialized.

Hence, the gettering layer loses its gettering capability against metallic contamination introduced in the backside grinding and package assembly.

Because the backside gettering layer is removed by backside grinding, it is not feasible to prevent characteristic deterioration caused by metallic contamination introduced after the backside grinding.

Nevertheless, since the backside receives grinding damages caused by the backside grinding, which produces gettering capability remains, albeit only slightly.

Yet, the gettering capability produced by a grinding damage layer is not sufficient and is not able to suppress the above-described characteristic deterioration.

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