Method and apparatus for depositing atomic layers on a substrate

Apparatus for depositing an atomic layer on a substrate, the apparatus comprising

• a deposition head having an output face that in use at least partly faces the substrate and is provided with a precursor-gas supply for supplying a precursor gas towards the substrate, wherein
• the output face has a substantially rounded shape defining a movement path of the substrate, the apparatus further comprising
• a mount for rotatably mounting the deposition head and comprising
• a driver arranged for rotating the deposition head so as to move the precursor gas supply along the substrate;
• said deposition head being constructed for having the supplied precursor gas react near, e.g. on, the substrate so as to form an atomic layer;
• the apparatus thus being arranged for depositing a stack of atomic layers while moving the precursor-gas supply along a rotation trajectory;
• and the apparatus comprises
• a gas source for providing precursor gas to the precursor gas supply via a gas flow path;
• and
• a gas switching structure arranged and constructed for switching between
• supplying the precursor gas from the precursor-gas supply towards the substrate over a first part of the rotation trajectory and
• interrupting supplying the precursor gas from said precursor-gas supply over a second part of the rotation trajectory
• wherein the gas switching structure comprise valves and valve control means, wherein
• the valves are arranged for affecting the gas flow through the gas flow path;
• and
• the valve control means are arranged for controlling the valves to interrupt or redirect the gas flow to the gas supply over the second part of the rotation trajectory.