International Business Machines Corporation

Richard R Garnache

Donald M Kenney

Badih El-Kareh

Nandor G Thoma

Ronald R Troutman

Ashwin K Ghatalia

Somanath Dash

A memory is provided which includes a semiconductor substrate having a major surface and a trench disposed therein having a longitudinal axis, storage means disposed on a given sidewall of the trench, switching means having a control element and a current carrying element disposed on the given sidewall of the trench between the storage means and the major surface of the substrate and coupled to the storage means, a first electrically conductive line disposed on the given sidewall in contact with the control element of the switching means and having a longitudinal axis arranged parallel to the longitudinal axis of the trench, and a second electrically conductive line disposed on the major surface of the semiconductor substrate in contact with the current carrying electrode of the switching means and having a longitudinal axis arranged orthogonal to the longitudinal axis of the trench.

Two square memory cells

A method or process is provided for making a semiconductor structure which includes the steps of forming in a semiconductor body a P/N junction and an opening in an insulating layer disposed on the surface of the semiconductor body. A trench is then formed in the semiconductor layer having a sidewall located along a given plane through the opening and through the P/N junction. An insulating material is disposed within the trench and over the insulating layer and a block or segment of material is located over the trench so as to extend a given distance from the trench over the upper surface of the body. The insulating material and the block are then etched so as to remove the block and the insulating material located along the sides of the block. A layer of low viscosity material is formed over the semiconductor body so as to cover the remaining portion of the insulating material, the layer of low viscosity material and the insulating material having similar etch rates. The layer of low viscosity material and the insulating material are then simultaneously etched directionally until all of the layer of low viscosity material is removed. Metallic contacts may now be formed on the surface of the semiconductor body without the concern that the metallic material will seep or enter into the trench causing a short at the P/N junction.

Method of making a contact to a trench isolated device

A method is provided for making complementary field effect transistors in a semiconductor layer having a first portion including an N type transistor with a channel region defined by N+ source and drain regions and having a second portion including a P type transistor with a channel region defined by P+ source and drain regions. An insulating layer is disposed over the first and second portions with thin insulating films formed over the channel regions. The steps of the method include applying a masking layer over the insulating layer having an opening over one of the portions, introducing a first impurity into the channel region of the one portion for channel tailoring purposes, depositing a first conductive refractory material on the thin insulating film located over the channel region of the one portion, removing the masking layer, introducing a second impurity into the channel region of the other portion for channel tailoring purposes and depositing a second conductive material on the thin insulating film located over the channel region of the other portion and in contact with the first conductive material. The first and second conductive materials have different work functions. The first conductive material is, preferably, platinum silicide while the second conductive material may be aluminum.

Method of making dense complementary transistors

High density VMOSFET devices, particularly single transistor memory cells, are provided by use of a series of simplified self-aligning process steps. Gate electrodes, source/drain regions and source/drain contacts are provided with the aid of an initial mask-less photoresist removal process in which a relatively thick layer of self-leveling photoresist is uniformly removed in order to define portions of a gate electrode within the recess of a V-groove. The gate electrode subsequently acts as a self-aligned mask to define implanted source/drain regions also within the V-groove and to enable second level interconnecting metallurgy contacts to be formed along the sidewalls of the V-groove.

V-MOS Device with self-aligned multiple electrodes

A method for providing self-aligned conductors in vertically integrated semiconductor devices which includes providing recesses in the surface of a semiconductor substrate for the fabrication of V-groove devices, providing a conductive layer over the surface and then applying a layer of masking material over the conductive layer to form a planar upper surface, selectively etching the masking material until it remains only in the recesses and then selectively etching the exposed portion of the conductive layer.

Growing community of inventors

South Burlington, VT, United States of America

Richard R Garnache