Abstract:
The invention relates to a process for the realisation of a high integration density power MOS device comprising the following steps of:
providing a doped semiconductor substrate (10) with a first type of conductivity (N); forming, on the substrate (10), a semiconductor layer (11) with lower conductivity (N-); forming, on the semiconductor layer (11), a dielectric layer (16) of thickness comprised between 3000 and 13000 A (Angstrom); depositing, on the dielectric layer (16), a hard mask layer; masking the hard mask layer by means of a masking layer; etching the hard mask layers and the underlying dielectric layer (16) for defining a plurality of hard mask portions (19) to protect said dielectric layer (16); removing the masking layer; isotropically and laterally etching said dielectric layer forming lateral cavities in said dielectric layer (16) below said hard mask portions (19); forming a gate oxide (15) of thickness comprised between 150 and 1500 A (Angstrom) depositing a conductor material (24) in said cavities and above the same to form a recess spacer (20), which is totally aligned with a gate structure (14) comprising said thick dielectric layer (16) and said gate oxide (15).
Abstract:
This invention relates to a method of fabricating a SOI (Silicon-On-Insulator) wafer suitable to manufacture electronic semiconductor devices and including a substrate of monocrystalline silicon with a top surface, and a doped buried region in the substrate. The method comprises at least one step of forming trench-like openings extended from the substrate surface down to the buried region, and comprises:
a selective etching step carried out through said openings to change said buried region of monocrystalline silicon into porous silicon; a subsequent step of oxidising the buried region that has been changed into porous silicon, to obtain an insulating portion of said SOI wafer.
Abstract:
The invention relates to a high integration density power MOS device comprising a substrate (10) of a doped semiconductor with a first type of conductivity whereon a semiconductor layer (11) with lower conductivity is formed, transistor elementary structures Ti (i=l..n) comprising body regions (12), arranged above in said semiconductor (11) inside which the source regions (13) are confined; the power MOS device comprises in each of the transistor elementary structures Ti (i=1..n) a gate structure (14) of the type with dual thickness comprising a first thin layer (15) of gate oxide onto which, at least partially, a dielectric layer (17) is overlapped having thickness greater than said first thin layer (15) and defining a central portion (17) delimited by lateral portions (18) of conductive material, said gate structure (14) further comprising a nitride upper portion (19) above the thick dielectric layer (17) and said lateral portions (18) of conductor material.
Abstract:
The invention relates to a process for the realisation of a high integration density power MOS device comprising the following steps of:
providing a doped semiconductor substrate (10) with a first type of conductivity (N); forming, on the substrate (10), a semiconductor layer (11) with lower conductivity (N-); forming, on the semiconductor layer (11), a dielectric layer (16) of thickness comprised between 3000 and 13000 A (Angstrom); depositing, on the dielectric layer (16), a hard mask layer; masking the hard mask layer by means of a masking layer; etching the hard mask layers and the underlying dielectric layer (16) for defining a plurality of hard mask portions (19) to protect said dielectric layer (16); removing the masking layer; isotropically and laterally etching said dielectric layer forming lateral cavities in said dielectric layer (16) below said hard mask portions (19); forming a gate oxide (15) of thickness comprised between 150 and 1500 A (Angstrom) depositing a conductor material (24) in said cavities and above the same to form a recess spacer (20), which is totally aligned with a gate structure (14) comprising said thick dielectric layer (16) and said gate oxide (15).
Abstract:
A trench (5) is formed in a semiconductor body (2); the side walls and the bottom of the trench are covered with a first dielectric material layer (9); the trench (5) is filled with a second dielectric material layer (10); the first and the second dielectric material layers (9, 10) are etched via a partial, simultaneous and controlled etching such that the dielectric materials have similar etching rates; a gate-oxide layer (13) having a thickness smaller than the first dielectric material layer (9) is deposited on the walls of the trench (5); a gate region (14) of conductive material is formed within the trench (5); and body regions (7) and source regions (8) are formed within the semiconductor body (2), at the sides of and insulated from the gate region (14). Thereby, the gate region (14) extends only on top of the remaining portions of the first and second dielectric material layers (9, 10).
Abstract:
The present invention describes a process for realizing buried microchannels (10) in an integrated structure (1) comprising a monocrystalline silicon substrate (2). Advantageously, according to the invention, the process provides to form in the substrate (2) at least one trench (4) and to obtain microchannels (10) starting from a deep cavity characterised by a small surface port obtained through anisotropic etching of the at least one trench (4). Microchannels (10) are completely buried in the substrate (2) in a completely microcrystalline structure.
Abstract:
The invention relates to a high integration density power MOS device comprising a substrate (10) of a doped semiconductor with a first type of conductivity whereon a semiconductor layer (11) with lower conductivity is formed, transistor elementary structures Ti (i=l..n) comprising body regions (12), arranged above in said semiconductor (11) inside which the source regions (13) are confined; the power MOS device comprises in each of the transistor elementary structures Ti (i=1..n) a gate structure (14) of the type with dual thickness comprising a first thin layer (15) of gate oxide onto which, at least partially, a dielectric layer (17) is overlapped having thickness greater than said first thin layer (15) and defining a central portion (17) delimited by lateral portions (18) of conductive material, said gate structure (14) further comprising a nitride upper portion (19) above the thick dielectric layer (17) and said lateral portions (18) of conductor material.