Glass composition for protecting semiconductor junction, method of manufacturing semiconductor device and semiconductor device

Patent metadata

Field	Value
Publication number	US-2016190026-A1
Application number	US-201615063420-A
Country	US
Kind code	A1
Filing date	Mar 7, 2016
Priority date	May 8, 2012
Publication date	Jun 30, 2016
Grant date	—

Abstract

Provided is a glass composition for protecting a semiconductor junction which contains at least SiC 2 , B 2 O 3 , Al 2 O 3 , ZnO and at least two oxides of alkaline earth metals selected from a group consisting of CaO, MgO and BaO, and substantially contains none of Pb, As, Sb, Li, Na and K, wherein an average linear expansion coefficient within a temperature range of 50° C. to 550° C. falls within a range of 3.33×10 −6 to 4.13×10 −6 . A semiconductor device having high breakdown strength can be manufactured using such a glass material containing no lead in the same manner as a conventional case where “a glass material containing lead silicate as a main component” is used.

First claim

1 . A semiconductor device, comprising:
a silicon-made semiconductor element having a pn junction; and a glass layer which covers the pn junction, wherein the glass layer is formed by baking a layer made of a glass composition, the glass composition comprises fine glass particles prepared from a material in a molten state obtained by melting a glass material which contains at least SiO 2 , B 2 O 3 , Al 2 O 3 , ZnO, and at least two oxides of alkaline earth metals selected from the group consisting of CaO, MgO and BaO, and substantially contains none of Pb, As, Sb, Li, Na and K, the content of SiO 2 falls within a range of 49.5 mol % to 64.3 mol %, the content of B 2 O 3 falls within a range of 8.4 mol % to 17.9 mol %, the content of Al 2 O 3 falls within a range of 3.7 mol % to 14.8 mol %, the content of ZnO falls within a range of 3.9 mol % to 14.2 mol %, and the content of the oxides of alkaline earth metals falls within a range of 7.4 mol % to 12.9 mol %, and an average linear expansion coefficient within a temperature range of 50° C. to 550° C. falls within a range of 3.33×10 −6 to 4.13×10 −6 .

2 . (canceled)

3 . The semiconductor device according to claim 1 , wherein
the average linear expansion coefficient within the temperature range of 50° C. to 550° C. falls within a range of 3.38×10 −6 to 4.08×10 −6 .

4 . The semiconductor device according to claim 1 , wherein
a total content of the content of SiO 2 and the content of B 2 O 3 falls within a range of 65 mol % to 75 mol %.

5 . The semiconductor device according to claim 1 , wherein
the glass composition contains, as the oxides of alkaline earth metals, all of CaO, MgO and BaO.

6 . The semiconductor device according to claim 5 , wherein
the content of CaO falls within a range of 2.0 mol % to 5.3 mol %, the content of MgO falls within a range of 1.0 mol % to 2.3 mol %, and the content of BaO falls within a range of 2.6 mol % to 5.3 mol %.

7 . The semiconductor device according to claim 1 , wherein
the glass composition contains, as the oxides of alkaline earth metals, CaO and BaO.

8 . The semiconductor device according to claim 7 , wherein
out of the oxides of alkaline earth metals,
the content of CaO falls within a range of 2.0 mol % to 7.6 mol %, and
the content of BaO falls within a range of 3.7 mol % to 5.9 mol %.

9 . (canceled)

10 . (canceled)

11 . A method of manufacturing a semiconductor device, the method comprising:
preparing a silicon-made semiconductor element having a pn junction; and forming a glass layer by baking a layer made of a glass composition such that the glass layer covers the pn junction, wherein the glass composition comprises fine glass particles prepared from a material in a molten state obtained by melting a glass material which contains at least SiO 2 , B 2 O 3 , Al 2 O 3 , ZnO, and at least two oxides of alkaline earth metals selected from the group consisting of CaO, MgO and BaO, and substantially contains none of Pb, As, Sb, Li, Na and K, the content of SiO 2 falls within a range of 49.5 mol % to 64.3 mol %, the content of B 2 O 3 falls within a range of 8.4 mol % to 17.9 mol %, the content of Al 2 O 3 falls within a range of 3.7 mol % to 14.8 mol %, the content of ZnO falls within a range of 3.9 mol % to 14.2 mol %, and the content of the oxides of alkaline earth metals falls within a range of 7.4 mol % to 12.9 mol %, and an average linear expansion coefficient within a temperature range of 50° C. to 550° C. falls within a range of 3.33×10 −6 to 4.13×10 −6 .

12 . (canceled)

13 . The method according to claim 11 , wherein
said preparing the semiconductor element comprises:
preparing a semiconductor base body having the pn junction parallel to a main surface; and
forming a trench extending from the main surface of the semiconductor base body to a depth below the pn junction, and
said forming the glass layer comprises forming the glass layer covering the pn junction exposed inside the trench.

14 . The method according to claim 13 , wherein said forming the glass layer comprises forming the glass layer such that the glass layer directly covers the pn junction exposed in the trench.

15 . The method according to claim 13 , wherein said forming the glass layer comprises
forming an insulation layer over the pn junction exposed in the trench, and forming the glass layer such that the glass layer covers the pn junction with the insulation layer interposed therebetween.

16 . The method according to claim 11 , wherein
said preparing the semiconductor element comprises forming the pn junction exposed on a surface of a semiconductor base body, and said forming the glass layer comprises forming the glass layer such that the glass layer covers the pn junction exposed on the surface of the semiconductor base body.

17 . The method according to claim 16 , wherein said forming the glass layer comprises forming the glass layer such that the glass layer directly covers the pn junction exposed on the surface of the semiconductor base body.

18 . The method according to claim 16 , wherein said forming the glass layer comprises
forming an insulation layer on the pn junction exposed on the surface of the semiconductor base body, and forming the glass layer such that the glass layer covers the pn junction with the insulation layer interposed therebetween.

19 . The method according to claim 11 , wherein said forming the glass layer comprises baking the layer made of the glass composition without causing crystallization.

20 . (canceled)

Assignees

• Shindengen Electric Mfg

Inventors

• Muyari Koya
• Ito Koji
• Ogasawara Atsushi
• Ito Kazuhiko

Classifications

• H10P14/69396

  the material containing at least one rare earth metal element, e.g. oxides of lanthanides, scandium or yttrium · CPC title

• H10P14/69391

  the material containing aluminium, e.g. Al2O3 · CPC title

• H10P14/69215

  the material being a silicon oxide, e.g. SiO2 · CPC title

• H10P14/6939

  characterised by the metal · CPC title

• H10P14/6536

  by exposure to radiation, e.g. visible light · CPC title