A method of forming self-aligned silicide devices which includes providing a silicon substrate having shallow trench isolation regions for defining a device area formed therein; then, forming sequentially a gate oxide layer, a polysilicon layer, a first titanium nitride layer, a titanium silicide layer, a second titanium nitride layer and a silicon nitride layer over the substrate. After a gate electrode is etched out from the above layers, a titanium layer is deposited over the device, and then a self-aligned titanium silicide layer is formed using a heating process. The use of a titanium silicide layer having protective top and bottom titanium nitride layers, compared with a single tungsten silicide layer in a conventional method, provides for a self-aligned silicide device having a rather low gate resistance; being free from narrow width effect of a titanium self-aligned silicide layer; is applicable to self-aligned contact window processes, and avoids the cross-diffusion of doped ions in the polysilicon layer of a dual gate electrode having a tungsten polycide layer.