u02dc 1200 u00b0 c at a heating rate of 1 u02dc 15 u00b0 c min step 2 raise the temperature of the furnace from 800 u02dc 1200 u00b0 c to 1400 u02dc 1600 u00b0 c at a heating speed of 0 5 u02dc 15 u00b0 c min and holding the temperature at 1400 u02dc 1600 u00b0 c for 3 u02dc 54 hours meanwhile injecting 0 6 u02dc 1 5 atm oxygen into the furnace step 3 lower the temperature of the furnace from 1400 u02dc 1600 u00b0 c to 800 u02dc 1200 u00b0 c at the speed of 0 5 u02dc 15 u00b0 c min and maintaining the oxygen pressure at 0 6 u02dc 1 5 atm and step 4 upon reaching 800 u02dc 1200 u00b0 c the furnace is naturally cooled down to room temperature 5 the 1 3 inch target is obtained and according to archimedes method the density of the target is 95 referring to fig2 and fig3 of indium tin distribution obtained by electron probe microanalysis epma according to fifth embodiment and sixth embodiment respectively the white spots indicate the distribution of the tin oxides it is clear that tin oxide distribution of the target made from powders prepared according to second embodiment is better than that obtained by traditional solid state target preparation method one of the features of this invention is that the powder homogeneity is improved by peptization aggregation of the hydroxyl compounds is inhibited during peptizing process as described above this can be proved by the particle size difference between.