A new method of performing a creep test on silicon single crystals is described. The experiment utilizes silicon wafers. The stress applied to the wafers is provided by a Si3N4film deposited by chemical vapor deposition on the front side of the wafer. The samples, i.e., silicon wafers with superposed Si3N4films, are annealed in a quartz tube at 1000–1100 °C. The creep curves obtained are classified into two types according to stress. One type is related to plastic deformation of the wafer; the other is an elastic deformation. These results are available for the use of Si3N4film in semiconductor technology.