Controllable integrated capacitive device

An integrated circuit comprising:

• a substrate;
• a first metal layer disposed over the substrate;
• a second metal layer disposed over the first metal layer;
• and
• a controllable capacitive device comprising a first element extending between a first fixing zone and a second fixing zone, the first element being controllable in flexion from a control zone, the first element comprising
• a first arm,
• a second arm spaced from the first arm, the first and second arms forming a U shape with the control zone,
• a first metal line located in a third layer disposed over the second metal layer and secured to the first arm, and
• a second metal line located in the third layer and secured to the second arm, the first metal line formed of a material having a different coefficient of thermal expansion than the first arm and the second metal line formed of a material having a different coefficient of thermal expansion than the second arm.

An integrated circuit comprising:

• a substrate;
• a first metal layer disposed over the substrate;
• a second metal layer disposed over the first metal layer;
• and
• a controllable capacitive device comprising
• a first element extending in a first direction between a first fixing zone and a second fixing zone and suspended over a fixed control electrode, the first element comprising
• a control plate facing the fixed control electrode,
• a first arm formed of a first material having a first coefficient of thermal expansion coefficient, and
• a first metal line secured to the first arm and formed of a second material having a second coefficient of thermal expansion coefficient, the first coefficient of thermal expansion coefficient being different than the second coefficient of thermal expansion coefficient, and
• a second element extending in cantilever fashion from the control plate and having a first width measured on the first direction, the second element comprising a movable plate at a free end of the second element, the movable plate having a second width measured on the first direction, wherein the second width is larger than the first width.

A method of fabricating an integrated circuit, the method comprising:

• disposing a first metal layer over an insulating region, wherein the first metal layer forms a lower wall, and wherein the first metal layer comprises a first fixed body, a second fixed body, a third fixed body, a first metallic portion, and a second metallic portion, wherein the first fixed body, the second fixed body, the third fixed body, the first metallic portion and the second metallic portion are spaced apart from each other;
• forming a first insulating layer over the first metallic portion;
• forming a first appendage over the first fixed body and a second appendage over the second fixed body;
• forming a first dielectric portion over the first appendage and a second dielectric portion over the second appendage;
• forming a second insulating layer over the first insulating layer and over the first and second dielectric portions, wherein the first insulating layer and the second insulating layer form a first inter-metal insulating region;
• forming a first via over the first metallic portion and a second via over the second metallic portion;
• disposing a second metal layer over the first inter-metal insulating region, wherein the second metal layer comprises a third metallic portion disposed over the first via, a fourth metallic portion disposed over the second via, and a suspended structure;
• forming a second inter-metal insulating region over the second metal layer;
• forming a third via over the third metallic portion and a fourth via over the fourth metallic portion, wherein the first via, third metallic portion and third via form a first wall, and the second via, fourth metallic portion, and fourth via form a second wall;
• forming a third metal layer over the second inter-metal insulating region, wherein the third metal layer comprising orifices, wherein the third metal layer forms a cowl, and wherein the lower wall, the first wall, the second wall, and the cowl form a housing;
• and
• removing the first and second inter-metal insulating region to form a cavity in the housing to form a hollow housing.