Device fabrication procedure

• US 4,374,391 A
• Filed: 09/24/1980
• Issued: 02/15/1983
• Est. Priority Date: 09/24/1980
• Status: Expired due to Term

• Current Assignee: Bell Telephone Laboratories, Inc. (Nokia Corporation)
• Original Assignee: Bell Telephone Laboratories, Inc. (Nokia Corporation)
• Inventors: Singh, Shobha, Camlibel, Irfan, Van Uitert, LeGrand G.
• Primary Examiner(s): Weisstuch, Aaron
• Application Number:
  US06/190,342
• Time in Patent Office: 874 Days
• Field of Search: 204/192 D, 106/54, 357/73, 357/30, 357/17, 428/428, 428/432
• US Class Current: 257/634
• CPC Class Codes: C03C 3/064 containing boron
• CPC Class Codes: C03C 3/089 containing boron
• CPC Class Codes: C23C 14/10 Glass or silica
• CPC Class Codes: H01L 21/02129 the material being boron or phosphorus doped silicon oxides, e.g. BPSG, BSG or PSG
• CPC Class Codes: H01L 21/02271 deposition by decomposition or reaction of gaseous or vapour phase compounds, i.e. chemical vapour deposition H01L21/02266 takes precedence
• CPC Class Codes: H01L 21/31625 Deposition of boron or phosphorus doped silicon oxide, e.g. BSG, PSG, BPSG
• CPC Class Codes: H01L 21/56 Encapsulations, e.g. encapsulation layers, coatings
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 31/02161 for devices characterised by at least one potential jump barrier or surface barrier

Abstract

A fabrication technique is described for making various devices in which a type of glass is used as a surface protection layer. The glass layers are put down by particle bombardment (generally sputtering) of a borosilicate glass target. Devices with such surface layers are also described. Such glass layers are highly advantageous as encapsulating material, diffusion barrier layers, etc., particularly for optical type devices and certain semiconductor devices. Particularly important is the preparation procedure for the glass target used in the bombardment process. The glass layers are moisture stable, act as excellent barriers against diffusion, and are usable up to quite high temperatures without cracking or peeling. The glass layers also provide long-term protection against atmosphere components including water vapor, oxygen, atmosphere pollution contaminants, etc.

Claims

1. A process for fabricating a device including the step of sputtering a borosilicate glass target material on at least part of a surface to form a borosilicate glass layer, characterized in that the borosilicate glass target material used in the sputtering procedure is prepared by a procedure comprising the steps of:

a. mixing together a substance A consisting essentially of SiO₂ with a substance B consisting essentially of B₂ O₃ ; and

b. heat treating the resulting mixture at a temperature between 1500 and 2100 degrees C. for at least six hours.

2. The process of claim 1 in which the mixing is done by ball milling for 5-15 hours.

3. The process of claim 1 in which at least 90 weight percent of the SiO₂ has particle size less than 10 microns and at least 90 weight percent of the B₂ O₃ has particle size less than 10 microns.

4. The process of claim 1 in which the heat treatment is carried out between 1600 and 1900 degrees C. for 6 to 12 hours.

5. The process of claim 4 in which the heat treatment is carried out in an inert atmosphere.

6. The process of claim 5 in which the inert atmosphere consists essentially of nitrogen and argon.

7. The process of claim 1 in which a sintering procedure is carried out after mixing but before heat treatment, said sintering procedure comprising heating the mixture to between 1000 and 1300 degrees C. for one to 10 hours.

8. The process of claim 7 in which the sintering procedure is carried out at 1150 ±

25 degrees C. for six hours.

9. The process of claim 1 in which the sputtering procedure is carried out with argon as the carrier gas.

10. The process of claim 9 in which the sputtering gas consists essentially of argon with trace amounts of oxygen.

11. The process of claim 1 in which the borosilicate glass target material consists essentially of up to 60 mole percent B₂ O₃ remainder SiO₂.

12. The process of claim 11 in which the borosilicate glass target material consists essentially of 5-45 mole percent B₂ O₃ remainder SiO₂.

13. The process of claim 1 in which the device is a semiconductor optical device and the borosilicate glass is sputtered on a surface consisting essentially of a III-V semiconductor.

14. The process of claim 13 in which the semiconductor compound is selected from the group consisting of gallium phosphide, silicon, indium phosphide, indium gallium arsenide, indium gallium arsenide phosphide, indium antimonide and germanium.

15. The process of claim 14 in which the semiconductor compound is selected from the group consisting of indium phosphide and indium gallium arsenide.

16. The process of claim 1 in which the process for fabricating a device includes a diffusion procedure carried out between 600 and 900 degrees C.

17. The process of claim 1 in which the borosilicate glass layer is used to encapsulate the device.

18. The process of claim 1 in which the resulting borosilicate glass target material is exposed to an annealing operation in the temperature range from 600 to 1400 degrees C. for one to 10 hours.

19. A device comprising a surface at least partially coated with a borosilicate glass layer, said layer fabricated by sputtering a borosilicate glass target material characterized in that the borosilicate glass target material used in the sputtering procedure is prepared by a procedure comprising the steps of

a. mixing together a substance A consisting essentially of SiO₂ in which at least 90 weight percent of the SiO₂ has a particle size less than 10 microns with a substance B consisting essentially of B₂ O₃ in which at least 90 weight percent of the B₂ O₃ has a particle size less than 10 microns and

b. heat treating the resulting mixture at a temperature between 1500 and 2100 degrees C. for at least 6 hours.

20. The device of claim 19 in which the mixing is done by ball milling for 5 to 15 hours.

21. The device of claim 19 in which the particle size is less than 1 micron.

22. The device of claim 19 in which the heat treatment is carried out between 1600 and 1900 degrees C. for 6 to 12 hours.

23. The device of claim 22 in which the heat treatment is carried out in an inert atmosphere.

24. The device of claim 23 in which the inert atmosphere consists essentially of nitrogen and argon.

25. The device of claim 19 in which a sintering procedure is carried out after mixing but before heat treatment, said sintering procedure comprising heating the mixture to between 1000 and 1300 degrees C. for 1 to 10 hours.

26. The device of claim 25 in which the sintering procedure is carried out at 1150 ±

25 degrees C. for approximately 6 hours.

27. The device of claim 26 in which the sputtering procedure is carried out with argon as the carrier gas.

28. The device of claim 27 in which the sputtering gas consists essentially of argon with trace amounts of oxygen.

29. The device of claim 19 in which the borosilicate glass layer consists essentially of up to 60 mole percent B₂ O₃ remainder SiO₂.

30. The device of claim 29 in which the borosilicate glass layer consists essentially of 5 to 45 mole percent B₂ O₃ remainder SiO₂.

31. The device of claim 19 in which the borosilicate glass layer at least partially covers a surface consisting essentially of a III-V semiconductor.

32. The device of claim 19 in which the III-V semiconductor is selected from the group consisting of gallium phosphide, silicon, indium phosphide, indium gallium arsenide, indium gallium arsenide phosphide, indium antimonide and germanium.

33. The device of claim 19 in which the device is an optical semiconductor device.

34. The device of claim 19 in which the device is an optical laser.

35. The device of claim 19 in which the device is a light-emitting diode.

36. The device of claim 19 in which the device is an optical detector.