Method for producing a transistor with self-aligned contacts and field insulation
AssigneeCommissariat a l'Energie Atomique
InventorSimon Deleonibus
Life of this patent
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Abstract
A process for making a MOS transistor. The transistor includes a source, a channel and drain formed on a portion of silicon film in a silicon-on-insulator type structure. A field insulation layer surrounds the film. A grid structure with insulated flanks is formed above the channel. Source and drain contacts are formed on the portion of the silicon film between the field insulation layer and the grid structure. The source and drain contacts are self-aligned on the grid structure and the field insulation layer is placed directly adjacent to the grid structure.
Claims20
A process for making a transistor on an SOI type support comprising a silicon oxide layer and a thin silicon film covering the silicon oxide layer, the process comprising the following steps:
- a) forming a stack comprising a grid insulator layer and a grid material layer in this order on the thin silicon film,
- b) forming a first etching mask on the stack according to a pattern corresponding to an active region of the transistor,
- c) etching the grid material layer, the grid insulation layer and the thin silicon film to form a column with first flanks defined according to the pattern of the first etching mask,
- d) forming a first insulating layer of electrical insulating material around the column, and planarizing a surface of this layer until the grid material layer of the column is exposed,
- e) etching the grid material layer in the column according to a second mask to form a grid structure with second flanks,
- f) forming a second insulating layer of electrical insulating material on the grid structure so as to electrically insulate the second flanks of the grid structure,
- g) forming source and drain regions in the thin silicon film by implantation of impurities, and
- h) forming contact areas on the grid structure in the source and drain regions.
Dependencies are inferred from the claim text.