20  US 8,703,386 B2  19  7.  The method of claim  5,  wherein the photoresist layer is  exposed imagewise using an ultraviolet radiation source at a  wavelength of 13.5 nm.  8.  The method of claim  5,  wherein the method further  comprises baking the disposed photoresist layer before said  exposing.  9.  The method of claim  5,  wherein the method further  comprises baking the disposed photoresist layer before said  developing.  10.  The method of claim  5,  wherein the method further  comprises transferring the pattern of features of the patterned  photoresist layer to the substrate.  11.  The method of claim  10,  wherein the method further  comprises baking the patterned photoresist layer before trans› ferring features of the patterned photoresist layer to the sub› strate.  12.  A photoresist composition, comprising:  a halide or alkoxide salt of a metal ion selected from the  group consisting of titanium  (IV), Niobium (V) and  Tantalum  (V);  an oxidatively stable organic carboxylic acid in an amount  of0.5 to 3.0 molar equivalents relative to moles of the  metal ion;  hydrogen peroxide in an amount of 1.0 to  10.0  molar  equivalents relative to moles of the metal ion•  ammonium hydroxide; and  ’  water;  the photoresist composition is suitable for forming a pho› toresist layer comprising a peroxo complex of the metal  ion in a process fore-beam lithography, x-ray lithogra› phy, and/or lithography utilizing an ultraviolet radiation  source having a wavelength that is in the range of  400  nm  to  10  nm, wherein the process includes imagewise  exposing the photoresist layer to form an exposed pho› toresist layer comprising i) exposed photoresist consist› ing essentially of exposed peroxo complex and ii) non› exposed photoresist consisting essentially of non› exposed peroxo complex, and removing the non› exposed photoresist using water or aqueous base  developer to form a patterned photoresist layer compris› ing the exposed photoresist.  wherein  13.  The photoresist composition of claim  12,  wherein the  organic carboxylic acid is present in an amount of0.75 to 1.5  molar equivalents relative to moles of the metal ion.  14.  The photoresist composition of claim  12,  wherein the  organic carboxylic acid is present in an amount of0.9 to 1.1  molar equivalents relative to moles of the metal ion.  *  *  *  *  *  6.  The method of claim  5,  wherein the photoresist layer is  exposed imagewise using an ultraviolet radiation source at a  wavelength that is in the range of  400  nm to  10  nm.  ii) disposing the photoresist composition on a surface of a  substrate and removing the solvent, thereby forming a  photoresist layer disposed on the substrate;  iii) imagewise exposing the photoresist layer to radiation  selected from the group consisting of e-beam, x-ray, and  ultraviolet (UV) radiation, thereby producing an  exposed photoresist layer comprising i) exposed photo› resist consisting essentially of exposed peroxo complex  and ii) non-exposed photoresist consisting essentially of  non-exposed peroxo complex; and  iv) removing the non-exposed photoresist by developing  the exposed photoresist layer with water and/or aqueous  base, thereby forming a layered structure comprising a  patterned photoresist layer disposed on the substrate, the  patterned photoresist layer comprising topographical  features comprising the exposed photoresist.  M’ is a metal ion selected from the group consisting of  tantalum (V), niobium (V), titanium (IV), and com- binations thereof,  L’ is an oxidatively stable organic carboxylate ligand,  and  wt% is based on total weight of the photoresist com- position;  wherein  w is  1  or 2,  x is an integer of  1  to  4,  y is an integer of  1  to  4,  u is  O or 1,  M’w(O 2 ML’)yOu has a charge ofO to -3,  C’ is animonium (NH 4  +),  k is an integer of0 to 3,  [C]k[M’w(02JxCL’)PuJ  (l), 15  5.  A method, comprising:  i) providing a photoresist composition comprising:  water;  about  0.1  wt% to about 30 wt% hydrogen peroxide, and  about  1  wt % to about 30 wt % of a peroxo complex  having a structure according to formula  (1):  [NH4]4[NbiO2MC 3 H 4 O 3 ) 4 O] wherein C 3 H 4 O 3  is lactate  (C3H4O3 -2),  [NH4h[Ta(O 2 MC 2 O 4 )]  wherein  C 2 O 4  1s  oxalate  (C2O4-2),  [NH4]2[Ti(O 2 MC 2 O 4 )] wherein C 2 O 4  is oxalate (C 2 O 4  - 2 ),  and  combinations thereof. 