Component comprising a variable capacitor

A method for forming a variable capacitor comprising:

• forming a cavity in an insulating substrate, a cavity portion substantially having the shape of a groove portion, the upper parts of the substrate located close to said groove portion forming two lateral edges, the depth of the groove portion increasing continuously from one of the edges to the bottom of the groove portion;
• covering the inside of the groove portion, at least to reach one of the edges and possibly covering one or two edges with a first conductive layer;
• filling the cavity with a sacrificial portion;
• covering the sacrificial portion, the upper substrate portions and possibly the portions of the first conductive layer placed above the lateral edges with an insulating layer and with a second conductive layer;
• etching the insulating layer and the second conductive layer to keep a bridge-shaped portion running over the groove portion and bearing against the lateral edges;
• and
• removing the sacrificial portion.