A method of forming an array of light active cells at a surface (42;252) of a substrate (44;250); each cell including parts of a series of layers over the surface of the substrate; providing the series of layers includes the steps of: providing a subseries of layers (254, 268,) having a topmost layer providing data lines (202, 206), the subseries further including scan lines (210, 212); depositing a first layer and patterning the first layer; the first patterned layer including conductive material; each cell including a cell electrode (50;200) that is part of the first patterned layer; providing a second patterned layer; the second patterned layer including dark matrix material that is conductive; each cell including a dark matrix that is part of the second patterned layer; providing a layer of dielectric material (52; 274) between the first and second patterned layers; whereby the first patterned layer and the second patterned layer are patterned so that the cell electrode (50;200) and the dark matrix of each cell overlap, the cell electrode and the dark matrix each having an overlap area (62, 64) where they overlap; the overlap area of the cell electrode, the overlap area of the dark matrix, and a part of the layer of dielectric material between them forming a storage capacitor for the cell; the second patterned layer is over the first patterned layer at least in the overlap area; electrically connecting the dark matrix of each cell to fixed potential circuitry to hold the dark matrix at a fixed potential characterized in that the topmost layer being a metal layer; depositing, after patterning of the topmost layer, an insulating layer, whereby the step of depositing said first layer is performed after the step of depositing said insulating layer. providing a subseries of layers (254, 268,) having a topmost layer providing data lines (202, 206), the subseries further including scan lines (210, 212); depositing a first layer and patterning the first layer; the first patterned layer including conductive material; each cell including a cell electrode (50;200) that is part of the first patterned layer; providing a second patterned layer; the second patterned layer including dark matrix material that is conductive; each cell including a dark matrix that is part of the second patterned layer; providing a layer of dielectric material (52; 274) between the first and second patterned layers; whereby the first patterned layer and the second patterned layer are patterned so that the cell electrode (50;200) and the dark matrix of each cell overlap, the cell electrode and the dark matrix each having an overlap area (62, 64) where they overlap; the overlap area of the cell electrode, the overlap area of the dark matrix, and a part of the layer of dielectric material between them forming a storage capacitor for the cell; the second patterned layer is over the first patterned layer at least in the overlap area; electrically connecting the dark matrix of each cell to fixed potential circuitry to hold the dark matrix at a fixed potential characterized in that the topmost layer being a metal layer; depositing, after patterning of the topmost layer, an insulating layer, whereby the step of depositing said first layer is performed after the step of depositing said insulating layer.