Abstract: The embodiments relate to a method for producing a solar cell having a rear-side contact with a tunnel barrier. A monocrystalline wafer having a front side and a rear side may be provided with silicon and a dopant. A tunnel barrier is produced on the wafer, and a polycrystalline or amorphous layer is deposited on the tunnel barrier. The polycrystalline or amorphous layer includes silicon and a dopant. The polycrystalline or amorphous layer is removed on the front side by gas-phase etching.

Abstract: A method and apparatus to modify the surface structure of a silicon substrate or deposited silicon layer in a controllable manner using gas only in an atmospheric environment, suitable for making photovoltaic (PV) wafer based devices. The method and apparatus comprising the steps of disposing the substrate or deposited layer on a moveable carrier; pre-heating the substrate or deposited layer; and moving the substrate or deposited layer for etching through an atmospheric reactor; under an etchant delivering module inside the reactor and applying at least one etchant in gas form at a controlled flow rate and angle to the substrate or deposited layer in the reactor, wherein the at least one etchant gas is selected from the group comprising fluoride-containing gases and chlorine-based compounds. The technical problem that has been solved is the provision of a high throughput dry etching method at atmospheric pressure.

Abstract: A method and apparatus to modify the surface structure of a silicon substrate or deposited silicon layer in a controllable manner using gas only in an atmospheric environment, suitable for making photovoltaic (PV) wafer based devices. The method and apparatus comprising the steps of disposing the substrate or deposited layer on a moveable carrier; pre-heating the substrate or deposited layer; and moving the substrate or deposited layer for etching through an atmospheric reactor; under an etchant delivering module inside the reactor and applying at least one etchant in gas form at a controlled flow rate and angle to the substrate or deposited layer in the reactor, wherein the at least one etchant gas is selected from the group comprising fluoride-containing gases and chlorine-based compounds. The technical problem that has been solved is the provision of a high throughput dry etching method at atmospheric pressure.