Composite substrate exhibiting a radiofrequency performance level below a predetermined threshold

Abstract

The invention relates to a composite substrate (1) exhibiting an HD2 performance level of less than -80 dBm over a temperature range of 0°C to 150°C. The composite substrate comprises a silicon base substrate (4) having a resistivity R between 100 Ohms.cm and 650 Ohms.cm at room temperature and a surface layer (2) formed of a single-crystal material deposited on the base substrate. It also comprises an interlayer structure (3) disposed between the base substrate (4) and the surface layer (2) having an electrical charge trapping layer (3b). The interlayer structure (3) has an equivalent air thickness EAT, in terms of effective electrical permittivity, greater than a minimum thickness EATmin = -2.67 × 10⁻³ × R + 3.3, when the resistivity R is expressed in Ohms.cm and the thickness in micrometers. Figure 3