As long as you file a joint tax return - your both are equally responsible for all taxes based on that tax return.
If you want to distance yourself from your spouse's tax liability - you are correct - the best way is to file separate tax returns.
Please be aware that in most situations separate tax returns will result larger combined tax liability. You may want to try both ways and determine the difference before filing.
Also - if you later change your mind later - you have three years to amend your tax return and file a joint tax return and still claim additional refund (if any).
However - you still may file a joint tax return and request the innocent spouse relief from the IRS - using the Form 8857 - http://www.irs.gov/pub/irs-pdf/f8857.pdf
By law, the IRS must contact your spouse - there are no exceptions, even for victims of spousal abuse or domestic violence - your spouse would be informed that you filed Form 8857 and will allow him participate in the process. If you are requesting relief from joint and several liability on a joint return, the IRS must also inform him of its preliminary and final determinations regarding your request for relief.
Please see more information in the IRS publication 971 - http://www.irs.gov/pub/irs-pdf/p971.pdf
Let me know if you need any help.
Tax Preparer
Taxes, Immigration, Labor Relations