NOVELTY - The method comprises forming a silicon oxide sub-layer having a net charge density of less than or equal to 2.1x 1011 Coulombs/cm2 on a rear surface of a p-type doped region formed in a solar cell substrate comprising semiconductor material, forming a silicon nitride sub-layer having a net charge density of less than or equal to 3x 1012 Coulombs/cm2 on the silicon oxide sub-layer, depositing (205) a backside contact layer on the silicon nitride sub-layer, forming backside contacts on the substrate, and patterning a multilayer rear surface passivation layer to expose the rear surface of the substrate.    USE - The method is useful for forming a multilayer rear surface passivation layer on a substrate of a solar cell.    ADVANTAGE - The method is capable of uniformly and easily forming the less dense multilayer rear surface passivation layer on the solar cell substrate thus enhancing the efficiency and durability, reducing the manufacturing cost and minimizing the carrier recombination of solar cell device.    DETAILED DESCRIPTION - The method comprises forming a silicon oxide sub-layer having a net charge density of less than or equal to 2.1x 1011 Coulombs/cm2 on a rear surface of a p-type doped region formed in a solar cell substrate comprising semiconductor material, forming a silicon nitride sub-layer having a net charge density of less than or equal to 3x 1012 Coulombs/cm2 on the silicon oxide sub-layer, depositing (205) a backside contact layer on the silicon nitride sub-layer, forming backside contacts on the substrate, patterning a multilayer rear surface passivation layer to expose the rear surface of the substrate, and depositing a backside contact layer on the silicon nitride sub-layer. The rear surface is opposite to a light receiving surface of the substrate. The silicon oxide sub-layer has a hydrogen concentration of 1-5 at.%, and a net negative charge density. The step of forming the silicon oxide sub-layer and the silicon nitride sub-layer comprises: flowing (201) a first process gas mixture into a process volume of a processing chamber, where the first process gas mixture comprises a silicon-containing gas and an oxidizing gas; depositing the silicon oxide sub-layer on the rear surface of the substrate; flowing (203) a second process gas mixture into the process volume, where the second process gas mixture comprises a silicon-containing gas and a nitrogen-containing gas; and depositing the silicon nitride sub-layer on the silicon oxide sub-layer. The silicon oxide sub-layer is deposited on the rear surface at greater than or equal to 2000 Angstrom per minute and a temperature of 100-200?C, and the silicon nitride sub-layer is deposited on the silicon oxide sub-layer at more than 1000 Angstrom per minute and a temperature of 250-200 degrees C. A ratio of the oxidizing gas to the silicon-containing gas in the first gas mixture is 5:1 to 10:1. A ratio of the silicon-containing gas to the nitrogen-containing gas in the second gas mixture is 5:1 to 10:1. The silicon oxide sub-layer has a thickness of 500-1000 Angstrom , and the silicon nitride sub-layer has a thickness of 250-1000 Angstrom . The multilayer rear surface passivation layer has a total thickness of 1000-1500 Angstrom . The backside contacts traverse the multilayer rear surface passivation layer to electrically couple the backside contact layer with the semiconductor material. An INDEPENDENT CLAIM is included for a solar cell device.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic view of a process flow diagram of a multilayer rear surface passivation layer formation process.    Flowing a first process gas mixture into a processing region of a processing chamber (201)    Depositing a silicon oxide layer on a rear surface of a substrate opposite to a light receiving surface of the substrate (202)    Flowing a second process gas mixture into the processing region (203)    Depositing a silicon nitride layer on the silicon oxide layer (204)    Depositing a backside contact layer on the silicon nitride layer. (205)