Patents by Inventor Francois M. Klaassen

Francois M. Klaassen has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4799092
    Abstract: An integrated circuit comprising complementary field effect transistors which are both of the normally-off depletion type. These transistors have, in the channel region a surface layer which has the same conductivity type as the adjoining source and drain zones. The surface layers comprise, per unit surface area, a quantity of dopant which is at least equal to the charge per unit surface area in the part of the substrate region which adjoins the surface layer and which is depleted if the threshold voltage is applied between the gate electrode and the source and drain zones. The gate electrodes comprise semiconductor material of opposite conductivity types.
    Type: Grant
    Filed: November 5, 1987
    Date of Patent: January 17, 1989
    Assignee: U.S. Philips Corporation
    Inventor: Francois M. Klaassen
  • Patent number: 4636826
    Abstract: In a semiconductor device, for example a SPS memory having narrow coplanar silicon electrodes, the electrodes are formed by etching grooves or slots having a width in the submicron range into a polycrystalline silicon layer with the slot width being defined by the oxidized edge of a silicon auxiliary layer. The electrodes are alternately covered by silicon oxide and by a layer comprising silicon nitride. The covered electrodes are first interconnected pairwise, whereupon they are separated from each other, and are provided with self-aligned contact windows. Thus, the very narrow electrodes can be contracted without technological problems and memory cells of very small dimensions are provided.
    Type: Grant
    Filed: November 27, 1985
    Date of Patent: January 13, 1987
    Assignee: U.S. Philips Corporation
    Inventors: Jan W. Slotboom, Henricus G. R. Maas, Johannes A. Appels, Francois M. Klaassen
  • Patent number: 4574468
    Abstract: A method of manufacturing a semiconductor device, for example an SPS memory having narrow coplanar silicon electrodes. The electrodes are formed by etching grooves or slots (10) having a width in the submicron range into a polycrystalline silicon layer (3), the slot width being defined by the oxidized edge (6) of a silicon auxiliary layer (5). The electrodes are alternately covered by silicon oxide and by a layer comprising silicon nitride. According to the invention, the electrodes formed covered by silicon oxide (3B, 13B) are first interconnected pairwise, whereupon they are separated from each other in a separate etching step and are provided with self-aligned contact windows (15). Thus, the very narrow electrodes can be contacted without technological problems and memory cells of very small dimensions can be obtained.
    Type: Grant
    Filed: October 4, 1984
    Date of Patent: March 11, 1986
    Assignee: U.S. Philips Corporation
    Inventors: Jan W. Slotboom, Henricus G. R. Maas, Johannes A. Appels, Francois M. Klaassen
  • Patent number: 4545110
    Abstract: A method of manufacturing a field effect device is set forth where the source and drain zones have extensions of an accurately and reproducibly determined length adjoining the gate electrode. According to the present invention, an oxygen-preventing insulating layer is formed on a first silicon layer forming the gate electrode, and a second silicon layer is provided on the oxygen-preventing layer. A part of the second silicon layer is removed and the edges substantially coincide with the edges of the gate electrode to be formed. The edges of the remaining part of the second silicon layer are oxidized. Through successive maskless selective etching steps, the first silicon layer is exposed and etched away at the area of the oxidized etched portions. The extensions of the source and drain zones are implanted through the openings thus obtained.
    Type: Grant
    Filed: September 7, 1984
    Date of Patent: October 8, 1985
    Assignee: U.S. Philips Corporation
    Inventors: Henricus G. R. Maas, Francois M. Klaassen, Johannes A. Appels
  • Patent number: 4233617
    Abstract: A field effect transistor of the V-MOST type in which the channel region comprises a more highly doped part which adjoins the source zone and a lower doped part which surrounds said region, said channel region adjoining the surface and surrounded by an insulation diffusion. The lower-doped part is depleted from the pn junction with the low-doped drain region up to the surface at a voltage which is lower than the breakdown voltage.
    Type: Grant
    Filed: January 16, 1979
    Date of Patent: November 11, 1980
    Assignee: U.S. Philips Corporation
    Inventors: Francois M. Klaassen, Johannes A. Appels