The present invention is generally directed to the field of semiconductor processing, and, more particularly, to a method of creating alignment keys for global wafer alignment. The fabrication of an integrated circuit device is a complicated multi-step process. Prior to the formation of the device itself, an array of various structures and/or layers are formed within a layer of semiconductor material, usually silicon. The various structures may include, for example, a shallow trench isolation (STI) structure, a polysilicon gate structure, various dielectric layers, various metallization layers, etc. Various techniques are used to create these structures. One technique is a reactive ion etching (RIE) process, which involves positioning a substrate within a plasma chamber, forming a polymer layer on the top surface of the substrate and etching the substrate to create a structure. Creating the polymer layer can be a problem with this process. A polymer is created when material is removed from the surface of the substrate by the reactive ions. An effective way to prevent the creation of a polymer is to remove the material from the surface of the substrate that is being etched, by using etching techniques that are not reactive ion. However, to create a structure using a reactive ion etching process, this material has to be left in place. Therefore, some means must be used to prevent the creation of a polymer, while creating the structure itself. This is the process of removing material in a non-reactive ion, non-chemical process. Another approach to solving this problem involves increasing the size of the structure itself. The amount of material left in the original etched area is increased, so that it is not ablated during etching. However, this size change can create another problem, as critical alignment of a subsequent mask layer can not be assured. Some techniques, such as phase shift masks, can be used to overcome these alignment issues, but these techniques are relatively expensive. In light of the foregoing, there is a need for a method of providing alignment keys to align a subsequent mask layer to an existing substrate surface. There is also a need for a method of making the alignment keys which does not increase the complexity of the fabrication process. In addition, there is a need for a method that is relatively inexpensive and reliable. These and other needs are met by the present invention. The present invention is directed to a method of creating alignment keys for global wafer alignment. The alignment keys are created by depositing a material into selected areas on the top of a substrate and removing the material within selected areas. This is done by depositing the material in a non-selective manner, e.g. all areas, within the selected areas, and then removing the material in the non-selected areas. In this manner, alignment keys are created that are defined by a selected area in the original substrate surface and a complementary area within the deposit. The present invention allows a subsequent mask layer to be aligned using an alignment key that can be created without etching, by the removal of material from non-selected areas of the substrate. The present invention is also directed to alignment keys that are created by depositing material into selected areas on the top of a substrate. However, in the present invention, an alignment key can be created within selected areas, or some other selected areas, without etching. Thus, unlike the prior art, one can create alignment keys that can be defined by a selected area in the original substrate surface, with a complementary area within the deposit, i.e. one can create alignment keys as soon as material is deposited. The present invention is also directed to a method of creating alignment keys for global wafer alignment on a substrate that has an alignment feature and a selected region within the alignment feature. A deposit of material is provided over the alignment feature and selected regions and the material is removed from within the alignment feature and unselected regions. This creates alignment keys that are defined by a selected area in the alignment feature and a complementary area within the deposit. The material is removed from within the alignment feature and unselected regions without etching. Therefore, one can create alignment keys that can be defined by a selected area in the alignment feature with a complementary area within the deposit, and without the need for etching. The present invention is also directed to a method of forming an alignment key on a substrate. The alignment key is defined by the removal of material from a first area in the substrate and a complementary area within a deposit of material over the substrate. These and other advantages and features of the present invention will become more readily apparent from the following detailed description of the invention which is provided in connection with the accompanying drawings.