Boron doped silicon oxide protective layer and method for making the same

A process for the deposition on a glass substrate of a protective boron doped silicon oxide layer comprising Si, O, and OH groups and wherein the boron content is comprised between 4 at 12 atomic %, comprising:

• a. providing a glass substrate,
• b. providing a plasma source, of linear hollow-cathode type, which source has a length, comprising at least one pair of hollow-cathode plasma generating electrodes, and comprises at least one electrode pair connected to an AC, DC or pulsed DC generator power source, for the deposition of said protective layer on the substrate,
• c. injecting a plasma generating reactive gas comprising oxygen in the plasma source's electrodes at a flow rate of between 125 and 750 sccm per linear meter of plasma source length;
• d. applying an electrical power to the plasma source of between 10 and 50 kW per linear meter of plasma source length, and,
• e. injecting a precursor gas at a flow rate of between 500 and 2500 sccm per linear meter of plasma source length, the precursor gas being injected into the plasma in at least between the electrodes of each electrode pair of the plasma source, depositing the protective layer on the glass substrate by exposing the substrate to the plasma of the plasma source.