http://rdf.ncbi.nlm.nih.gov/pubchem/patent/JP-S5550655-A
Outgoing Links
| Predicate | Object |
|---|---|
| assignee | http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_f4ff9ddf728a7e1a0b36c9cc38b89ad6 |
| classificationIPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/H01L21-331 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/H01L29-73 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/H01L29-72 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/H01L29-08 |
| filingDate | 1978-10-09^^<http://www.w3.org/2001/XMLSchema#date> |
| inventor | http://rdf.ncbi.nlm.nih.gov/pubchem/patentinventor/MD5_7e7a3fd643b6432c75e6a4a2385bc436 |
| publicationDate | 1980-04-12^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber | JP-S5550655-A |
| titleOfInvention | Preparation of semiconductor device |
| abstract | PURPOSE: To improve pressure resisting property, by heightening the accuracy of the cutting of a mask of chemical etching by using an acid-proof metallic film and a photo-resist film as the mask when forming mesa grooves on a transistor for high power. n CONSTITUTION: A p-type base layer 2 is made up on a n-type Si substrate 1, n-type emitter regions 3, 3' are diffusion-built up to the layer 2 and the upper portions of a plurality of element forming regions are beforehand covered with SiO 2 films 4, 4'. An Al film 10 and a photo-resist film 15 are stacked and coated on the whole surface, and the film 15 is built up in a plurality of square masks 15', 15" by mounting measure-like opening portions 16a, 16a' to the film 15 in shapes that are made correspond to separating regions among elements. Openings 16b, 16b' are formed to the film 10 by means of etching by employing a mixed liquid of phosphoric acid, acetic acid and nitric acid, mesa grooves 17, 17' are produced by etching portions extending over the substrate 1 from the exposed portions of the layer 2 by using nitric acid and fluoric acid and the resist film and the A° film, which become useless, are removed. Thus, the excellent mesa grooves 17, 17' are obtained because the masks are not exfoliated between the films 10 and 15. n COPYRIGHT: (C)1980,JPO&Japio |
| isCitedBy | http://rdf.ncbi.nlm.nih.gov/pubchem/patent/JP-H0441976-B2 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/JP-S60110229-A http://rdf.ncbi.nlm.nih.gov/pubchem/patent/JP-S61289826-A |
| priorityDate | 1978-10-09^^<http://www.w3.org/2001/XMLSchema#date> |
| type | http://data.epo.org/linked-data/def/patent/Publication |
Incoming Links
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