Infineon Technologies Ag

Qimonda Ag

Thomas Ruder

Thomas Schuster

Grit Schwalbe

A semiconductor structure having a plurality of gate stacks on a semiconductor substrate provided with a gate dielectric. The gate stacks have a lower first layer made of polysilicon, an overlying second layer made of a metal silicide, and an upper third layer made of an insulating material, and a sidewall oxide on the sidewalls of the first and second layers. The sidewall oxide is thinned or removed on one of the sidewalls, and the gate stacks have sidewall spacers made of the insulating material.

Method for the production of a semiconductor substrate comprising a plurality of gate stacks on a semiconductor substrate, and corresponding semiconductor structure

The invention relates to a process for patterning dielectric layers. A photoresist layer is applied to the dielectric layer and patterned. Then, the pattern which has been predetermined by the resist mask is transferred to the dielectric layer. The incineration of the resist mask is carried out a temperature of 50&#xb0; C. to 200&#xb0; C., with the oxygen plasma being generated from a gas which has an oxygen content of 40 to 60% by volume. During a subsequent step of cleaning the patterned dielectric layer using dilute hydrofluoric acid, the trenches which have been introduced into the dielectric layer are widened to a significantly lesser extent than after incineration under the conditions which have previously been customary.

Method for patterning dielectric layers on semiconductor substrates

Method for the production of a semiconductor structure comprising a plurality of gate stacks on a semiconductor substrate which serve as control electrodes for a respective selection transistor of a corresponding memory cell comprising a storage capacitor. Gate stacks are provided next to one another on the substrate provided with a gate dielectric wherein the gate stacks have a lower first layer made of polysilicon, an overlying second layer made of metal silicide, and an upper layer made of silicon nitride. A sidewall oxide is formed on uncovered sidewalls of the first and second layers of the gate stacks, and at least partly the sidewall oxide is removed on those sidewalls of the gate stacks serving as a control electrode which are remote from the associated storage capacitor. Silicon nitride sidewall spacers are then formed on the gate stacks.

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Dresden, Germany

Thomas Ruder