A method for sealing an access opening to a cavity comprises the following steps: providing a layer arrangement having a first layer structure and a cavity arranged adjacent to the first layer structure, wherein the first layer structure has an access opening to the cavity, performing a CVD layer deposition for forming a first covering layer having a layer thickness on the first layer structure having the access opening, and performing an HDP layer deposition with a first and second substep for forming a second covering layer on the first covering layer, wherein the first substep comprises depositing a liner material layer on the first covering layer, wherein the second substep comprises partly backsputtering the liner material layer and furthermore the first covering layer in the region of the access opening, and wherein the first and second substeps are carried out alternately and repeatedly a number of times.