High breakdown voltage passive element and high breakdown voltage passive element manufacturing method

Abstract

Warping of a semiconductor wafer occurring due to a difference in the thermal expansion rates of an insulating film and the semiconductor wafer is restricted. Therefore, processing failures and conveying failures in the manufacturing process, as well as cracking of the semiconductor wafer, are restricted. Provided is a high breakdown voltage passive element including a substrate, a lower metal layer and upper metal layer stacked on the substrate, and an insulating unit formed between the lower metal layer and upper metal layer, wherein the insulating unit has a first insulating film whose thermal expansion rate is lower than the thermal expansion rate of the substrate, and a second insulating film, formed on the first insulating film, whose thermal expansion rate is higher than the thermal expansion rate of the substrate.

What is claimed is: 
     
         1 . A high breakdown voltage passive element, comprising:
 a substrate;   a lower metal layer and upper metal layer stacked on the substrate; and   an insulating unit formed between the lower metal layer and upper metal layer,   the insulating unit having   a first insulating film having a thermal expansion rate lower than a thermal expansion rate of the substrate, and   a second insulating film, formed on the first insulating film, having a thermal expansion rate higher than the thermal expansion rate of the substrate.   
     
     
         2 . A high breakdown voltage passive element, comprising:
 a substrate;   an insulating unit formed on an upper surface side of the substrate, and   a metal layer provided in one plane on the upper surface side of the insulating unit,   the insulating unit having   a first insulating film, having a thermal expansion rate lower than a thermal expansion rate of the substrate, and a second insulating film, having a thermal expansion rate higher than the thermal expansion rate of the substrate, stacked on the upper surface side of the substrate.   
     
     
         3 . The high breakdown voltage passive element according to  claim 1 , wherein
 a ratio between a thickness of the first insulating film and a thickness of the second insulating film is such as to offset warping of the substrate.   
     
     
         4 . The high breakdown voltage passive element according to  claim 2 , wherein
 a ratio between a thickness of the first insulating film and a thickness of the second insulating film is such as to offset warping of the substrate.   
     
     
         5 . The high breakdown voltage passive element according to  claim 1 , wherein
 the first insulating film is a plasma TEOS film, and   the second insulating film is a polyimide film or a polybenzoxazole film.   
     
     
         6 . The high breakdown voltage passive element according to  claim 2 , wherein
 the first insulating film is a plasma TEOS film, and   the second insulating film is a polyimide film or a polybenzoxazole film.   
     
     
         7 . The high breakdown voltage passive element according to  claim 1 , wherein
 the first insulating film is a plasma CVD film, and   the second insulating film is a PSG film, a BPSG film, or an NSG film.   
     
     
         8 . The high breakdown voltage passive element according to  claim 2 , wherein
 the first insulating film is a plasma CVD film, and   the second insulating film is a PSG film, a BPSG film, or an NSG film.   
     
     
         9 . The high breakdown voltage passive element according to  claim 1 , wherein
 the insulating unit has two first insulating films sandwiching the second insulating film.   
     
     
         10 . The high breakdown voltage passive element according to  claim 2 , wherein
 the insulating unit has two first insulating films sandwiching the second insulating film.   
     
     
         11 . The high breakdown voltage passive element according to  claim 1 , wherein
 the insulating unit has two second insulating films sandwiching the first insulating film.   
     
     
         12 . The high breakdown voltage passive element according to  claim 2 , wherein
 the insulating unit has two second insulating films sandwiching the first insulating film.   
     
     
         13 . The high breakdown voltage passive element according to  claim 1 , wherein
 a thickness of an insulating film on an uppermost layer in the insulating unit is greater than a thickness of other insulating films.   
     
     
         14 . The high breakdown voltage passive element according to  claim 2 , wherein
 a thickness of an insulating film on an uppermost layer in the insulating unit is greater than a thickness of other insulating films.   
     
     
         15 . The high breakdown voltage passive element according to  claim 1 , wherein
 a thickness of the insulating unit is 5 μm or more.   
     
     
         16 . The high breakdown voltage passive element according to  claim 1 , wherein
 a thickness of each of the first insulating film and second insulating film is 0.5 to 3.0 μm.   
     
     
         17 . The high breakdown voltage passive element according to  claim 1 , wherein
 a ratio between a thickness of the first insulating film and a thickness of the second insulating film is 1:1 to 2:1.   
     
     
         18 . A high breakdown voltage passive element manufacturing method, comprising:
 a stage of providing a lower metal layer on a front surface side of a substrate;   a stage of providing an insulating unit wherein a first insulating film, having a thermal expansion rate lower than a thermal expansion rate of the substrate, and a second insulating film, having a thermal expansion rate higher than the thermal expansion rate of the substrate, are stacked on a front surface side of the lower metal layer; and   a stage of providing an upper metal layer on a front surface side of the insulating unit, wherein   a temperature at which one of the first insulating film or second insulating film is formed is a temperature such that does not cause properties of another, already formed, film to change.   
     
     
         19 . A high breakdown voltage passive element manufacturing method, comprising:
 a stage of providing on a substrate a first insulating film, having a thermal expansion rate lower than a thermal expansion rate of the substrate, and a second insulating film, having a thermal expansion rate higher than the thermal expansion rate of the substrate; and   a stage of providing a metal layer on the first insulating film and second insulating film, wherein   a temperature at which one of the first insulating film or second insulating film is formed is a temperature such that does not cause properties of another, already formed, film to change.   
     
     
         20 . A device, comprising:
 a substrate;   a first insulating film above the substrate, the first insulating film having a thermal expansion rate lower than a thermal expansion rate of the substrate;   a second insulating film above the first insulating film, the second insulating film having a thermal expansion rate higher than the thermal expansion rate of the substrate; and   at least a portion of an electromagnetic coil above the second insulating film.   
     
     
         21 . The device of  claim 20 , further comprising at least another portion of an electromagnetic coil between the substrate and the first insulating film. 
     
     
         22 . The device of  claim 20 , wherein the first insulating film includes tetraethoxysilane. 
     
     
         23 . The device of  claim 20 , wherein the second insulating film includes at least one of polyimide or polybenzoxazole. 
     
     
         24 . The device of  claim 20 , wherein the first insulating film and the second insulating film are included in a plurality of stacked layers between the substrate and the at least a portion of an electromagnetic coil, the stacked layers including a first insulating film alternating with a second insulating film a plurality of times. 
     
     
         25 . The device of  claim 24 , wherein one of the stacked layers closest to the at least a portion of an electromagnetic coil is a thickest one of the stacked layers.