Methods of forming integrated assemblies include stacked memory decks

A method of forming an assembly, comprising:

• forming a first deck having a first stack of alternating first and second tiers, and having a region extending through the first stack;
• a first material being within the first tiers and within the region;
• a second material being within the second tiers;
• the first material being a conductive material and the second material being an insulative material;
• forming an inter-deck structure over the first deck;
• the inter-deck structure comprising an inter-deck material;
• forming a second deck over the inter-deck structure;
• the second deck having a second stack of alternating third and fourth tiers;
• the third and fourth tiers comprising third and fourth materials, respectively;
• the fourth material being an insulative material;
• forming an opening which extends through the second stack and the inter-deck structure, and to the region;
• and
• removing the first material from the region with an etch selective for the first material relative to the third and fourth materials.