Stmicroelectronics S.r.l.

Sgs-Thomson Microelectronics S.r.l.

Patrizia Sonego

Maurizio Bacchetta

Luca Pividori

Elio Colabella

A method of depositing a dielectric ply structure to optimize the planarity of electronic devices that include a plurality of active elements having gate regions laid across the substrate as discrete parallel lines, such as the bit lines of memory cells. In accordance with the principles of the present invention, the plurality of bit lines may be isolated from one another by the dielectric ply structure to provide a planar architecture onto which an optional conductive layer may be deposited. The resulting planarization avoids the typical shortcomings of the prior art, such as the lack of electrical continuity in the word lines or their excessively high electrical resistance from slenderized portions in the conductive sections due to poor planarity of the surfaces upon which the conductive layer is deposited.

Planarization structure and method for dielectric layers

A method is for forming an intermediate dielectric layer to optimize the planarity of electronic devices integrated on a semiconductor which incorporate non-volatile memories. The insulating dielectric is deposited from a liquid state source comprising silicon oxides and organics of the resist type. The liquid dielectric layer is evenly spread by a spinning technique providing good levels of planarity. Solidification, referred to as polymerization, is achieved through a low-temperature thermal cycle. Since this dielectric layer cannot be used as such to isolate the semiconductor substrate from the overlying metallization plane on account of the presence of organics forming a source of impurities, it is arranged for the layer to be encapsulated between two dielectric layers of silicon oxide as deposited from a plasma. To make the highly planarizing intermediate dielectric layer consistent with the other two encapsulating dielectric layers, a rapid annealing step is carried out in an oven under a gas stream, subsequently to the polymerization step. The rapid annealing step is also utilized to densify the upper dielectric layer encapsulating the highly planarizing intermediate dielectric layer.

Process for realizing an intermediate dielectric layer for enhancing the planarity in semiconductor electronic devices

Method of planarizing a semiconductor device by depositing a dielectric

A method of depositing a layered dielectric structure to improve the planarity of electronic devices which include a plurality of active elements having gate regions laid across the substrate as discrete parallel lines, such as the bit lines of memory cells. The bit lines are isolated from one another by a layered dielectric structure to provide a planar architecture onto which an optional conductive layer may be deposited. The dielectric structure is formed from a highly planarizing dielectric layer of the SOG type spun over a first insulating dielectric layer and solidified by means of a thermal polymerization process. After solidifying the dielectric layer, it is subjected to a rapid thermal annealing treatment.

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Milan, Italy

Patrizia Sonego