Silicon based planar micro thermoelectric generators (μTEGs) were realized by CMOS compatible technology then were evaluated to harvest low to high level of heat. The μTEGs are build up with a thermopile periodically suspended onto dielectric membranes. The thermopile is based on a poly-Silicon (pSi) TE layer; it is a series of pSi/Au or Al thermocouples (TC) patterned into a zig-zag strip that covers a surface about a third of cm². This planar topology with membranes and long TC result in modules with a high thermal resistance [1] and a performance slightly impacted by the TE thermal conductivity but rather efficiently improved by any increase of the TE power factor (PF=α².σ, α is the Seebeck coefficient, σ the electrical conductivity). The presented modules integrate different kinds of pSi layers, with a PF varying from 3 μW/K²/cm, for standard P doped pSi, to 24 μW/K²/cm for “optimum” pSi obtained by very high dose implantation doping with B or As and annealing. The evaluation of their performance is carried out using a heat concentrator placed above the μTEG and periodically in thermal contact with the thermopile at half of the junctions. The characterisation is done by injecting power to a resistance printed on the upper surface of the concentrator. The power is varied from 0 to 10 W/cm². A periodic gradient of temperature ΔT is created at each TC. This results in a Seebeck open-circuit voltage Vs that is seen to vary linearly with the input power. Typically, for an input heat flux density of 4W/cm², ΔT experienced by each TC varies up to 30, 100 and 150K for respectively 10-, 5- and 2-membranes based modules, which is consistent with the whole structure modelling. The optimum behaviour is experimentally obtained for 5-membranes based μTEGs. In these cases, Vs is in the range 6-15V depending on the pSi properties and corresponds to a maximum output power Pmax in the range 49 – 306 μW/cm² on adapted loads. The best performance is obtained for μTEGs integrating highly B doped pSi layer (large PF). Surprisingly, the As+P codoped-based μTEGs are only moderately better than those based on standard pSi (Pmax is 4 times better though the PF is a decade higher). This can be partly explained by an increase of the thermal conductivity associated to a microstructure modification via codoping. On the other hand, microstructure changes in highly B doped pSi has already been reported to improve the PF [2]. In this work we show that it is also effective to make performant planar modules. ----- References: [1] Z. Yuan et al., Sensors and Actuators A 221 (2015) 67-76. [2] For instance D. Narducci et al, Phys. Stat. Sol. A. 211 (2014) 1255-1258.