HF

Helmut Foell

SA Siemens Aktiengesellschaft: 2 patents #73 of 995Top 8%
📍 Troisdorf, DE: #5 of 23 inventorsTop 25%
Overall (1989): #26,333 of 140,708Top 20%
2
Patents 1989

Issued Patents 1989

Showing 1–2 of 2 patents

Patent #TitleCo-InventorsDate
4874484 Etching method for generating apertured openings or trenches in layers or substrates composed of n-doped silicon Volker Lehmann 1989-10-17
4841239 Method and measuring instrument for identifying the diffusion length of the minority charge carriers for non-destructive detection of flaws and impurities in semiconductor crystal bodies Volker Lehmann 1989-06-20