Semiconductor integrated circuit device and its manufacturing method

A semiconductor integrated circuit device comprising electrically writable nonvolatile memory elements each including, in a semiconductor region:

• a source region;
• a drain region;
• a channel formation region interposed between said source region and said drain region;
• and
• a control gate electrode,
• wherein two of said channel formation regions are disposed independently over respective opposing side surfaces of each of rectangular-parallelepiped semiconductor pillars, said drain region connected to said two channel formation regions is formed in an upper portion of said rectangular-parallelepiped semiconductor pillar, each of a plurality of insulator pillars is disposed between adjacent ones of said semiconductor pillars to form a row such that said channel forming regions are not faced toward side surfaces of said insulators pillars, a first insulating film is provided between each of said channel formation regions and said control gate electrode, a semiconductor film is provided over said first insulating film, a nonconductive charge trap film is provided over said first insulating film, a second insulating film is provided over said nonconductive charge trap film, and electrons are trapped primarily in a charge trap level at an interface between said semiconductor film and the nonconductive charge trap film.

A method for manufacturing a semiconductor integrated circuit device, comprising at least the steps of:

• alternately forming, over a semiconductor substrate, trenched isolation regions, each comprised of insulator material, and semiconductor active regions, each comprised of a semiconductor material, in stripes, performing etching with respect to said semiconductor active regions and said trenched isolation regions in stripes in directions orthogonal to said trenched isolation regions and semiconductor active regions in stripes to form rectangular-parallelepiped semiconductor pillars and rectangular-parallelepiped insulator pillars such that each of insulator pillars is disposed between adjacent ones of said semiconductor pillars to form a row;
• forming channel formation regions in respective side surface portions of each of said rectangular-parallelepiped semiconductor pillars, depositing a multilayer film comprised of a first oxide film, a nitride film, and a second oxide film over each of said channel formation regions, and forming word lines comprised of side spacers each made of a conductive film;
• and
• forming a drain region in an upper portion of each of said rectangular-parallelepiped semiconductor pillars.

A method for manufacturing a semiconductor integrated circuit device, comprising at least the steps of:

• alternately forming, over a semiconductor substrate, trenched isolation regions, each comprised of insulator material, and semiconductor active regions, each comprised of a semiconductor material, in stripes, performing etching with respect to said semiconductor active regions and said trenched isolation regions in stripes in directions orthogonal to said trenched isolation regions and semiconductor active regions in stripes to form rectangular-parallelepiped semiconductor pillars and rectangular-parallelepiped insulator pillars, such that each of said insulator pillars is disposed between adjacent ones of said semiconductor pillars to form a row;
• forming channel formation regions in respective side surface portions of each of said rectangular-parallelepiped semiconductor pillars, depositing a multilayer film comprised of a first oxide film, a polysilicon film, a nitride film, and a second oxide film over each of said channel formation regions, and forming word lines comprised of side spacers each made of a conductive film;
• and
• forming a drain region in an upper portion of each of said rectangular-parallelepiped semiconductor pillars.

A method of manufacturing a semiconductor integrated circuit device, comprising steps of:

• forming a conductive film covering projecting island regions which are formed in stripes and regions adjacent to said projecting island regions;
• wherein an insulating film is formed between said projecting island regions and said conductive film;
• and
• performing anisotropic etching to said conductive film by using a mask covering contact regions to be formed from said conductive film so as to form conductive lines on side surfaces of said projecting island regions and said contact regions integrated with said conductive lines,
• wherein said anisotropic etching is performed so as to form an electrode of a peripheral circuit element in a peripheral circuit forming region by using said mask,
• wherein said insulating film includes a film for discretely accumulating charge therein, and
• wherein each of said conductive lines serves as a gate electrode of a nonvolatile memory element and has a shape of a side wall spacer formed in self-alignment to said side surface of a corresponding one of said projecting island regions.

A method of manufacturing a semiconductor integrated circuit device, comprising steps of:

• forming a conductive film covering projecting island regions each extending in a first direction such that an insulating film is formed between said projecting island regions and said conductive film;
• performing anisotropic etching to said conductive film so as to form conductive lines on side surfaces of said projecting island regions such that each of said conductive lines serves as a gate electrode of an element and has a shape of a side wall spacer formed in self-alignment to said side surface of a corresponding one of said projecting island regions;
• and
• after said anisotropic etching step, partially removing said conductive lines adjacent in a second direction crossing to said first direction by using a mask extending over said projecting island regions adjacent in said second direction.