Process for forming differential spaces in electronics device integrated on a semiconductor substrate

Abstract

A forms spacers in a electronic device integrated on a semiconductor substrate that includes: first and second transistors each comprising a gate electrode projecting from the substrate and respective source / drain regions. The process comprises: forming in cascade a first protective layer and a first conformal insulating layer of a first thickness on the whole electronic device; forming a first mask to cover the first transistor; removing the first conformal insulating layer not covered by the first mask; removing the first mask; forming a second conformal insulating layer of a second thickness on the whole device; and removing the insulating layers until the protective layer is exposed to form first spacers of a first width on the side walls of the gate electrodes of the first transistor and second spacers of a second width on the side walls of the gate electrodes of the second transistor.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to a process for forming of differential spacers in electronic devices integrated on a semiconductor substrate.[0003]The invention particularly, but not exclusively, relates to a process for forming differential spacers in floating gate non-volatile memory devices and the following description is made with reference to this field of application by way of illustration only.[0004]2. Description of the Related Art[0005]As it is well known, non-volatile memory electronic devices, for example of the Flash type, integrated on semiconductor substrate comprise a matrix of non-volatile memory cells organized in rows, called word lines, and columns, called bit lines.[0006]Each single non-volatile memory cell comprises a MOS transistor wherein the gate electrode, arranged above the channel region, is floating, i.e., it shows high impedance in DC towards all the other terminals of the same cell and of ...

AI Technical Summary

Benefits of technology

[0015]One embodiment of the invention is a process for forming, in a same electronic device integrated on a semiconductor substrate, electronic components with spacers of different widths, having such structural and functional characteristics as to minimize the overall dielectric constant of the dielectric layers which separate some electronic components of the device, thereby overcoming the limits and / or drawbacks still limiting the devices formed according to the prior art.

Problems solved by technology

The process steps for forming these advanced technology LV transistors, especially those pertaining to the formation of the junction implants (source and drain regions) and of the spacers are particularly complex.

In particular, the integration of the high performance LV transistors with the HV transistors handling the high voltages for writing to the memory cells is further complex, with the need of introducing differential spacers and junction implants.

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