Patent Number: 
Section: claims

1. A method for evaluating a lithography mask, the method comprises:directing, by electron optics, primary electrons towards a pellicle that is positioned between the electron optics and the lithography mask; wherein the primary electrons exhibit an energy level that allows the primary electrons to pass through the pellicle and to impinge on the lithography mask;detecting, by at least one detector, detected emitted electrons and generating detection signals; wherein detected emitted electrons are backscattered electrons generated as a result of an impingement of the primary electrons on the lithography mask;masking, by a filter, secondary electrons from detection by the at least one detector, the secondary electrons emitted from the pellicle due to an interaction of the backscattered electrons with the pellicle; andprocessing, by a processor, the detection signals to provide information about the lithography mask. 2. The method according to claim 1, comprising masking secondary electrons emitted from the pellicle due to an interaction of the primary electrons with the pellicle. 3. The method according to claim 1, wherein the at least one detector comprises multiple backscattered electron detection elements. 4. A system for evaluating a lithography mask, the system comprises:electron optics for directing primary electrons towards a pellicle that is positioned between the electron optics and the lithography mask; wherein the primary electrons exhibit an energy level that allows the primary electrons to pass through the pellicle and to impinge on the lithography mask;at least one detector for detecting detected emitted electrons and for generating detection signals; wherein detected emitted electrons are backscattered electrons generated as a result of an impingement of the primary electrons on the lithography mask;at least one mask for masking secondary electrons from detection by the at least one detector, wherein the secondary electrons are generated as a result if impingement of the backscattered electrons on the pellicle; anda processor for processing the detection signals to provide information about the lithography mask. 5. The system according to claim 4, wherein the system is arranged to mask secondary electrons emitted from the pellicle due to an interaction of the primary electrons with the pellicle. 6. The system according to claim 4, wherein the at least one detector comprises multiple backscattered electron detection elements. 7. A method for evaluating a lithography mask, the method comprises:directing, by electron optics, primary electrons towards a pellicle that is positioned between the electron optics and the lithography mask;wherein the primary electrons exhibit an energy level that allows the primary electrons to pass through the pellicle and to impinge on the lithography mask;detecting, by at least one detector, detected emitted electrons and generating detection signals;wherein detected emitted electrons are backscattered electrons generated as a result of an impingement of the primary electrons on the lithography mask;masking, by a filter, secondary electrons from detection by the at least one detector, the secondary electrons emitted from the pellicle due to an interaction of the primary electrons with the pellicle; andprocessing, by a processor, the detection signals to provide information about the lithography mask; andmasking secondary electrons emitted from the pellicle due to an interaction of the backscattered electrons with the pellicle. 8. The method according to claim 7, wherein the at least one detector comprises multiple backscattered electron detection elements.