Selectively leached thermally stable cutting element in earth-boring tools, earth-boring tools having selectively leached cutting elements, and related methods

A method of forming a cutting element, comprising:

• providing a diamond-containing material over a substrate;
• sintering the diamond-containing material with a homogenized binder to form a cutting table attached to an end of the substrate and comprising inter-bonded diamond particles;
• during the sintering, converting portions of the homogenized binder within interstitial spaces between the inter-bonded diamond particles into one or more non-catalytic compounds and one or more metallic phases comprising one or more catalytic metallic phases;
• and
• selectively removing the one or more catalytic metallic phases from the cutting table to form a first region substantially free of catalytic metallic phases and comprising inter-bonded diamond particles and the non-catalytic compounds and voids within the interstitial spaces between the inter-bonded diamond particles of the first region, and a second region comprising inter-bonded diamond particles and the one or more non-catalytic compounds and the one or more catalytic metallic phases within interstitial spaces between the inter-bonded diamond particles of the second region,
• wherein the first region of the cutting table has a content of elemental metal of at least about 2.6 wt %.