Commissariat &#xc0; L'&#xc9;nergie Atomique Et Aux &#xc9;nergies Alternatives

Valentin Bacquie

Nicolas Posseme

A method is provided for etching a dielectric layer covering a top and a flank of a three-dimensional structure, the method including: a first etching of the dielectric layer, including: a first fluorine-based compound and oxygen, the first etching being performed to: form a first protective layer on the top and form a second protective layer on the dielectric layer, a second etching configured to remove the second protective layer while retaining a portion of the first protective layer, the first and the second etchings being repeated until removing the dielectric layer located on the flank of the structure, and before deposition of the dielectric layer, a formation of an intermediate protective layer between the top and the dielectric layer.

Method of engraving a three-dimensional dielectric layer

A method for forming spacers of a gate of a transistor is provided, including: providing an active layer surmounted by a gate; forming a dielectric layer covering the gate and the active layer, the dielectric layer having lateral portions, and basal portions covering the active layer; anisotropically modifying the basal portions by implantation of hydrogen-based ions in a direction parallel to the lateral sides of the gate, forming modified basal portions; annealing desorbing the hydrogen from the active layer and transforming the modified basal portions into second modified basal portions; and removing the modified basal portions by selective etching of the modified dielectric material with respect to the non-modified dielectric material and with respect to the semiconductive material, so as to form the spacers on the lateral sides of the gate.

Method of forming the spacers of a transistor gate

A method is provided for forming spacers of a gate of a transistor, including: providing an active layer surmounted by a gate; forming a dielectric layer covering the gate and the active layer, the dielectric layer having lateral portions and basal portions; anisotropically modifying the basal portions by implantation of light ions, forming modified basal portions; and removing the modified basal portions by selective etching, so as to form the spacers on the lateral flanks of the gate from the unmodified lateral portions, in which, before the removing step, the anisotropic modification of the basal portions includes n successive implantation phases having implantation energies Γi (i=1 . . . n) which are distinct from each other, the n phases being configured to implant the light ions at different nominal implantation depths.

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Grenoble, France

Valentin Bacquie