公开(公告)号：JPH1187491A

公开(公告)日：1999-03-30

申请号：JP18839898

申请日：1998-07-03

Applicant: ST MICROELECTRONICS SRL

Inventor： QUEIROLO GIUSEPPE ,  OTTAVIANI GIAMPIERO ,  CEROFOLINI GIANFRANCO

IPC: H01L21/302 ,  H01L21/265 ,  H01L21/301 ,  H01L21/304 ,  H01L21/306 ,  H01L21/76

Abstract: PROBLEM TO BE SOLVED: To prevent an interlattice defect formed due to impact from being shifted by keeping the temperature of a crystalline target at a low level when ions are implanted at atomic weight and kinetic energy suitable for rendering the crystal amorphous up to a design depth within a range defined by an ion implantation mask. SOLUTION: When a crystal is a single crystal silicon substrate, the substrate is kept at -196 deg.C (boiling point of nitrogen), for example, and ions are implanted accurately up to a design depth corresponding to the kinetic energy of accelerating ion. Consequently, a crystal matrix is rendered amorphous through the majority shift mechanism of atom in a crystal lattice to be implanted. Since low temperature is kept in order to prevent diffusion of point defect occurring in a solid due to impact, the implanted ions are prevented from being diffused into an adjacent crystal lattice. Consequently, a spatial distribution of templanted ions characteristic of an isolation step face occurring simultaneously on both the side wall and the bottom face at an amorphous part can be attained.

公开(公告)号：DE69733471D1

公开(公告)日：2005-07-14

申请号：DE69733471

申请日：1997-07-03

Applicant: ST MICROELECTRONICS SRL

Inventor： QUEIROLO GIUSEPPE ,  OTTAVIANI GIAMPIERO ,  CEROFOLINI GIANFRANCO

IPC: H01L21/302 ,  H01L21/265 ,  H01L21/301 ,  H01L21/304 ,  H01L21/306 ,  H01L21/76

Abstract: A process for cutting a trench in a silicon monocrystal in areas defined by a mask comprises forming a mask that defines the etch area on the surface of a monocrystallin silicon wafer eventually covered by a thin layer of oxide; implanting ions with a kinetic energy and in a dose sufficient to amorphize the silicon down to a predefined depth within the defined area, while maintaining the temperature of the wafer sufficiently low to prevent relaxation of point defects produced in the silicon and diffusion of the implanted ions in the crystal lattice of the silicon adjacent to the amorphized region; and heating the implanted wafer causing dislodgment and expulsion of the amorphized portion in correspondence of the interface with the adjacent crystal lattice of the silicon.