Process for forming apertures in silicon bodies
Large value capacitor
Anodic etching method for the detection of electrically active defects in silicon
Photoelectrochemical etching of n-type silicon
Method for obtaining full oxide isolation of epitaxial islands in silicon utilizing selective oxidation of porous silicon
Fabrication of cleaved semiconductor lasers Patent #: 4689125
ApplicationNo. 193760 filed on 05/13/1988
US Classes:438/750, To same side of substrate205/655, With irradiation or illumination257/E21.216Electrolytic etching (EPO)
ExaminersPrimary: Valentine, Donald R.
Attorney, Agent or Firm
Foreign Patent References
International ClassC25F 003/12
Foreign Application Priority Data1987-05-27 DE
AbstractThe present invention provides the production of apertured openings or trenches in layers or substrates composed of n-doped silicon proceeding in an electrolytic way, whereby the silicon is connected as a positively polarized electrode of an electrolysis cell containing an agent that contains hydrofluoric acid. Hole structures having highly variable cross-section can be reproducibly manufactured with the method of the invention and holes can be localized by prescribing nuclei. The invention can be used in the manufacture of trench cells in memory modules, insulating trenches in LSI semiconductor circuits, large-area capacitors (varicaps), and in contacting more deeply disposed layers in disconnectable and voltage-controlled thyristors.