the following description is of the best - contemplated mode of carrying out the invention . this description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense . the scope of the invention is best determined by reference to the appended claims . embodiments of the invention , which provides a fluid injection apparatus , will be described in greater detail by referring to the drawings that accompany the invention . it is noted that in the accompanying drawings , like and / or corresponding elements are referred to by like reference numerals . the invention is not limited to any particular fluid driving device or driving method , which is not particularly mentioned in the specification . the invention can further comprise any fluid driving device , such as thermal driven bubble or piezoelectric actuator , or driving method . fig2 shows a plan view of a fluid injection apparatus . this is not prior art for the purpose of determining the patentability of the present invention . this merely shows a problem found by the inventors . referring to fig2 , a fluid injection apparatus 200 comprises a plurality of nozzles 202 . the nozzles are not arranged in a row or in a column to inject ink to a right location , not affected by scanning sequence of the nozzles 202 . a distance l 1 between a fluid injection unit 204 and the manifold 206 , however , is different with the distance l 2 between another fluid injection unit 204 and the manifold 206 . thus , performance of the fluid injection units 200 may be affected . to eliminate performance non - uniformity of fluid injection units , an embodiment of the invention provides a fluid injection apparatus comprising fluid injection units having substantially uniform performance . fig3 a ˜ fig3 c are intermediate plan views of a fluid injection apparatus of an embodiment of the invention . referring to fig3 a , a substrate 300 , such as silicon or glass , is provided . in a preferred embodiment of the invention , the substrate 300 is a silicon substrate . next , a structure layer 304 is formed on the substrate 300 to define a plurality of chambers 306 on or in the substrate 300 , as shown in fig3 b . in a preferred embodiment of the invention , the chambers 306 are not disposed along a column direction or a row direction , but along a slanting line or a zigzag line , or in a particular pattern . formation of the chambers 306 may comprise the following steps . as shown in fig3 a , a patterned sacrificial layer 302 is formed on areas predetermined for forming chambers overlying a substrate 300 . referring to fig3 b , a structure layer 304 is formed on the patterned sacrificial layer 302 and the substrate 300 . next , the structure layer 304 is patterned , for example by conventional lithography or etching , to form a plurality of nozzles 308 corresponding to the patterned sacrificial layer . note that at least two nozzles 308 are not arranged in a column or in a row orientation . arrangement of the nozzles 308 can be depended on a system of the fluid injection apparatus to optimize scanning performance . in an embodiment of the invention , the nozzles 308 are arranged along a slighting line , a curve or a zigzagged line for optimizing scanning performance of the fluid injection apparatus . fig3 d is a top view of a fluid injection apparatus of an embodiment of the invention , in which fig3 c is a local view of fig3 d . fig3 e is a cross section along i - i ′ line of fig3 d . referring to fig3 c , fig3 d and fig3 e , backside of the substrate 300 is patterned to form a manifold 310 , exposing the sacrificial layer 302 . next , the sacrificial layer is removed to form the chambers 306 , each connecting the manifold 310 through a chamber inlet 312 . a fluid , preferably an ink , flows from the manifold 310 to the chambers 306 through the chamber inlets 312 , and further be ejected through the nozzles 308 . in another embodiment of the invention , the chamber inlet 312 comprises a first inlet 311 and a second inlet 313 disposed in the manifold 310 , both adjacent to the sidewall 314 of the manifold 310 and the chamber 306 . the first inlet 311 and the second inlet 313 are separated by the structure layer 304 ( or structure layer can also be referred as a nozzle plate ). preferably , the sidewall 314 of the manifold 310 extends substantially along a line , parallel to another line connecting the chamber inlets 320 . thus , distances between the nozzles 308 and the manifold 310 are substantially fixed when each chamber inlet 312 and nozzle 308 is separated by the same distance . the invention , however , is not limited thereto . the principle of the embodiment is that sidewalls of the manifold 310 corresponds to the arrangement of the nozzle 308 , thus the distance from the manifold 310 to the nozzles 308 is fixed . preferably , distance between a sidewall of the manifold and each nozzle is substantially the same . more preferably , the distances between a sidewall 314 of the manifold 310 and centers of the nozzles 308 are substantially the same . the fluid injection apparatus further comprises a fluid driving device , such as a heater ( not shown in the figures for simplicity ), for driving fluid in the fluid injection apparatus . the invention is not limited to a particular fluid driving device or driving method . it can be designed and manufactured according to product spec or process window . accordingly , in a preferred embodiment of the invention , the distances between the fluid injection units 320 , at least two of the fluid injection units 320 not arranged in a column or in a row , and the manifold 310 are substantially the same . thus , the fluid injection units 320 have more uniform performance and stability and reliability of the fluid injection apparatus is increased . while the invention has been described by way of example and in terms of the preferred embodiments , it is to be understood that the invention is not limited to the disclosed embodiments . to the contrary , it is intended to cover various modifications and similar arrangements ( as would be apparent to those skilled in the art ). therefore , the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements .