Category:Standardized tests in the United States
Category:English-language education1. Field of the Invention
The present invention relates to a semiconductor device having a silicon-on-insulator (SOI) structure and a method of manufacturing the same. More specifically, the invention relates to a semiconductor device having a SOI structure including an SOI substrate having a thin single-crystal semiconductor layer formed on a supporting substrate and a method of manufacturing the same.
2. Description of the Related Art
In recent years, a great deal of attention has been paid to a semiconductor device having a silicon-on-insulator (SOI) structure. The SOI structure has a single-crystal silicon thin film formed on an insulating film (e.g., silicon dioxide) formed on a silicon substrate. With this SOI structure, it is possible to manufacture high-speed devices due to complete isolation between elements by the insulating film and reduced parasitic capacitance between wirings.
A known SOI structure is a silicon-on-insulator structure having a thin single-crystal silicon layer formed on a supporting substrate (e.g., silicon substrate). Such a structure is formed by bonding a surface of a silicon substrate, which is a thin single-crystal silicon layer, through a bonding layer formed of, e.g., oxygen, and then grinding and polishing the silicon substrate to a predetermined thickness. A method of forming the thin single-crystal silicon layer on the supporting substrate is disclosed in, e.g., Japanese Patent Laid-Open Publication No. 63-161754.
In the above known SOI structure, however, a thin single-crystal silicon layer is formed on the supporting substrate by a bonding method, and therefore it is difficult to secure a desired bonding strength between the thin single-crystal silicon layer and the supporting substrate. As a result, a thin single-crystal silicon layer may peel from the supporting substrate. When a thin single-crystal silicon layer is peeled from the supporting substrate, the thin single-crystal silicon layer is broken. Therefore, the thin single-crystal silicon layer must be bonded to the supporting substrate with a high bonding strength. The use of a material of a higher melting point as a bonding layer is conceivable. The bonding layer may be formed, e.g., by a method disclosed in, e.g., Japanese Patent Laid-Open Publication No. 4-142654 ac619d1d87
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