Semiconductor sensor having suspended thin-film structure and method for fabricating thin-film structure body

A method for fabricating a thin-film structure body, comprising:

• disposing a sacrificial layer on a substrate;
• forming a thin film above said substrate with said sacrificial layer interposed therebetween;
• modifying an upper surface of said thin film after a formation of said thin film is completed so that distribution of stress existing in a thickness direction of said thin film is controlled to reduce a bending moment exerted on said thin film;
• and
• removing said sacrificial layer to make said thin film movable with respect to said substrate;
• wherein said modifying of said upper surface of said thin film includes implanting a stress-adjusting substance into said upper surface, and said stress-adjusting substance is selected from the group consisting of an impurity atom which shows the same conductivity type as said thin film, an atom making up said thin film, and an inert atom.

A method for fabricating a thin-film structure body, comprising:

• disposing a sacrificial layer on a substrate;
• forming a thin film above said substrate with said sacrificial layer interposed therebetween;
• modifying an upper surface of said thin film after a formation of said thin film is completed so that distribution of stress existing in a thickness direction of said thin film is controlled to reduce a bending moment exerted on said thin film;
• and
• removing said sacrificial layer to make said thin film movable with respect to said substrate;
• wherein said modifying of said upper surface of said thin film includes locally etching said upper surface.

A method for fabricating a thin-film structure body, comprising:

• disposing a sacrificial layer on a substrate;
• forming a thin film above said substrate with said sacrificial layer interposed therebetween;
• modifying an upper surface of said thin film after a formation of said thin film is completed so that distribution of stress existing in a thickness direction of said thin film is controlled to reduce a bending moment exerted on said thin film;
• and
• removing said sacrificial layer to make said thin film movable with respect to said substrate;
• wherein said modifying of said upper surface of said thin film is performed after applying a temperature greater than a maximum temperature that the thin-film structure body will be subjected to during use.

A method for fabricating a thin-film structure body, comprising:

• disposing a sacrificial layer on a substrate;
• forming a thin film above said substrate with said sacrificial layer interposed therebetween;
• modifying an upper surface of said thin film after a formation of said thin film is completed so that distribution of stress existing in a thickness direction of said thin film is controlled to reduce a bending moment exerted on said thin film;
• and
• removing said sacrificial layer to make said thin film movable with respect to said substrate;
• wherein said modifying of said upper surface of said thin-film includes implanting a stress-adjusting substrate into said upper surface, annealing is performed after said implanting of said stress-adjusting substrate, and a temperature of said annealing is set higher than the maximum temperature during actual utilization of said thin-film structure body and is set lower than a sintering temperature of a metal disposed on said substrate.

A method for fabricating a thin-film structure body, comprising:

• disposing a sacrificial layer on a substrate;
• forming a thin film above said substrate with said sacrificial layer interposed therebetween;
• modifying an upper surface of said thin film after a formation of said thin film is completed so that distribution of stress existing in a thickness direction of said thin film is controlled to reduce a bending moment exerted on said thin film;
• and
• removing said sacrificial layer to make said thin film movable with respect to said substrate;
• wherein said modifying of said upper surface of said thin film is performed on less than all of said upper surface of said thin film.

A method for fabricating a thin-film structure body, comprising:

• disposing a sacrificial layer on a substrate;
• forming a thin film above said substrate with said sacrificial layer interposed therebetween;
• modifying an upper surface of said thin film after a formation of said thin film is completed so that distribution of stress existing in a thickness direction of said thin film is controlled to reduce a bending moment exerted on said thin film;
• and
• removing said sacrificial layer to make said thin film movable with respect to said substrate;
• wherein said modifying of said upper surface of said thin film and said removing of said sacrificial layer are performed using an identical mask.

A method for fabricating a thin-film structure body, comprising:

• disposing a sacrificial layer on a substrate;
• forming a thin film above said substrate with said sacrificial layer interposed therebetween by depositing a lower film and thereon an upper film having a different internal stress state from said lower film, thereby forming said thin film, said lower film and said upper film being composed of a homogeneous material;
• and
• removing said sacrificial layer to make said thin film movable with respect to said substrate;
• wherein said depositing of said lower and upper films includes varying a deposition temperature between said lower and upper films.

A method for fabricating a thin-film structure body, comprising:

• disposing a sacrificial layer on a substrate;
• forming a thin film above said substrate with said sacrificial layer interposed therebetween by depositing a lower film and thereon an upper film having a different internal stress state from said lower film, thereby forming said thin film, said lower film and said upper film being composed of a homogeneous material;
• and
• removing said sacrificial layer to make said thin film movable with respect to said substrate;
• wherein said depositing of said lower and upper films includes varying a deposition pressure between said lower and upper films.

A method for fabricating a thin-film structure body, comprising:

• forming a semiconductor element on a substrate, having an impurity diffusion region;
• forming a sacrificial layer on said substrate;
• forming a thin film material on said sacrificial layer;
• patterning said thin-film material using a mask, whereby a configuration of said thin-film structure body is determined;
• implanting impurities into a surface of said patterned thin-film material while said semiconductor element is covered with said sacrificial layer to prevent said impurities from being implanted in said semiconductor element;
• and
• removing said sacrificial layer to cause a space to be formed between said substrate and said patterned thin-film materials.

A method for fabricating a thin-film structure body, comprising:

• forming a sacrificial layer on a semiconductor substrate;
• depositing a plurality of thin films having differing internal-stress states on said sacrificial layer so as to form a stack of thin films, said plurality of thin films being composed of a homogeneous material;
• and
• etching said sacrificial layer below said stack to thereby cause said stack movable with respect to said substrate;
• wherein all of said plurality of thin films are collectively made of the same homogeneous material.

A method for fabricating a thin-film structure body, comprising:

• forming a sacrificial layer on a semiconductor substrate;
• depositing a plurality of thin films having differing internal-stress states on said sacrificial layer so as to form a stack of thin films, said plurality of thin films being composed of a homogeneous material;
• and
• etching said sacrificial layer below said stack to thereby cause said stack movable with respect to said substrate;
• wherein stress adjustment within said stack is performed by causing widths parallel to said semiconductor substrate of two mutually contiguous thin films to differ.

A method for fabricating a thin-film structure body, comprising:

• forming a sacrificial layer on a semiconductor substrate;
• depositing a plurality of thin films having differing internal-stress states on said sacrificial layer so as to form a stack of thin films, said plurality of thin films being composed of a homogeneous material;
• and
• etching said sacrificial layer below said stack to thereby cause said stack movable with respect to said substrate;
• wherein said plurality of thin films are amorphous silicon.

A semiconductor sensor comprising:

• a semiconductor substrate;
• and
• a movable member of beam structure disposed above said semiconductor substrate with a predetermined gap interposed therebetween, wherein:
• said movable member is structured by laminating a plurality of thin films having differing internal stress states so as to form a stack of thin films, said plurality of thin films being composed of a homogeneous material;
• and
• stress adjustment within said stack is performed by causing widths parallel to said semiconductor substrate of two mutually contiguous thin films to differ.