Photoshop automatically adds a vector mask whenever I use shape tool.how do I stop it from adding vector masks?
When using the shape tool you can choose three different modes:
Shape Layers. This mode creates the shape you want with a vector mask, the one you're currently using.
Paths. This mode will draw a vector path with anchors in the shape that you chose, you can then use the anchor selection tools to modify the shape, right click to fill, stroke or convert to selection.
Fill Pixels. This mode allows you to create raster pixel filled shapes when you drag it out, so on mouse release the shape you dragged will be automatically filled with no vector masks.
These tool should be at the top left under the context menus:
Play around with these and see which one suits your needs best :) I always use the Paths mode, as it allows me to edit the shape after the initial creation and before filling/stroking. :)