Process for etching a polycrystalline Si(1-x)Ge(x) layer or a stack of polycrystalline Si(1-x)Ge(x) layer and of a polycrystalline Si layer, and its application to microelectronics
AssigneeFrance Telecom
InventorsCédric Monget, Sophie Vallon, Olivier Joubert
Life of this patent
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Abstract
The process for etching a polycrystalline Si1−xGex layer or a stack includes a polycrystalline Si1−xGex layer and of a polycrystalline Si layer, deposited on a substrate and including, at its surface, a mask of inorganic material, includes main etching step in which the said layer or the said stack is anisotropically etched, using the said mask, by means of a high-density gas plasma of a gas mixture consisting of chlorine (Cl2) and of either nitrogen (N2) or ammonia (NH3) or of a nitrogen/ammonia mixture.
Claims26
Process for etching a layer of a polycrystalline Si1−xGex [(0<×≦1)] (0.5≦×≦1) mixture deposited on a substrate or for etching a stack comprising a first layer of a polycrystalline Si1−xGex [(0<×≦1)] (0.5≦×≦1) mixture deposited on a substrate and a second silicon layer deposited on the first layer, the said layer or the said stack including, on its surface, a mask of inorganic material, comprising a main etching of the said layer or the said stack in which the said Si1−xGex layer or the said stack is anisotropically etched, using the said mask, by means of a high-density gas plasma of a gas mixture comprising chlorine (Cl2) and either nitrogen (N2) or ammonia (NH3) or a nitrogen/ammonia mixture.
Process for etching a layer of a gate structure material comprising a polycrystalline Si1−xGex (0<×≦1) mixture deposited on a substrate, comprising:
- forming a mask of inorganic material upon a portion of the layer of the gate structure material;
- and
- anisotropically etching an unmasked portion of the layer of the gate structure material using a high-density gas plasma of a gas mixture comprising chlorine (Cl2) and ammonia (NH3).
Process for etching a layer of a gate structure material comprising a polycrystalline Si1−xGex (0.5≦×≦1) mixture deposited on a substrate, comprising:
- forming a mask of inorganic material upon a portion of the layer of the gate structure material;
- and
- anisotropically etching an unmasked portion of the layer of the gate structure material using a high-density gas plasma of a gas mixture comprising chlorine (Cl2) and nitrogen (N2).
Dependencies are inferred from the claim text.