Dense array of horizontal carbon nanotubes (CNTs) connected to electrodes is a basic building block for devices in a wide field of applications such as interconnect lines or micro-electromechanical systems (MEMS) for sensing for instance. For interconnects, maximizing the CNT density means maximizing the number of parallel conduction paths, which is necessary to be competitive with copper. For gas sensing, a membrane made of high density CNTs should promote a high sensitivity by developing a high detection surface. Despite the recognized superior properties of CNTs, their adoption as alternative materials remains limited due to integration difficulties at a wafer scale and low CNT density. Here, two integration schemes fully compatible with the processing of 200 mm wafers using conventional silicon technologies are innovatively proposed to manufacture highly dense horizontal CNT membranes at a wafer scale.